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Rzeppa
06-09-2011, 06:50 PM
I have an issue with my fully smogged 1987 FJ60 where it sometimes will idle just fine and other times will stall when pulling to a stop. We are only talking about full normal operating temperature. I have eliminated the EGR system as a potential cause by disconnecting the line between the vacuum modulator and the EGR valve and capping the line, so the EGR isn't coming on. I also verified that the idle cut solenoid is operating.

Backing up in the story a bit, she used to do fine until I had to do some work to get her through emissions testing. She failed the first try. So I changed out the air filter element, backed the static timing back to stock 7 from the 17 she was at, changed the main jet from 147 to 138, and dumped 4 bottles of Heet into the remaining 5 gallons of fuel, and then she passed with flying colors. She ran like crap though and stalled at idle a lot. After passing, I put the static timing back to the 17 that she was running good at and put the 147 jet back in, filled the tank back up to dilute the methanol. That made her run a lot better, but there is this intermittent stalling issue that is really making her a PITA for my wife to drive her.

It is almost as if the fuel (or timing?) is connected to a LSPV: when you come to an abrupt stop, as in traffic and press the clutch in, she will often stall. If you slow down really gently to your stop, no stall. The idle adjustment mixture screw is set at 3 turns. I tried other settings, both leaner and richer and neither seemed to make any difference. And besides - she used to work just fine before I messed with her to pass emissions. For now the brute force fix is setting the idle too high, around 1200-1400 RPM. Whenever she gets much below 1000 she wants to stall.

There are no obvious vacuum leaks, although I haven't done a thorough test for those. She runs great just driving around. If there is a vacuum leak, it would only be under the circumstance of coming to an abrupt stop and putting the clutch in. I figure there are about 3 or 4 other emissions subsystems which might cause this symptom other than EGR and idle fuel cut solenoid, so I am coming to the Rising Sun forum to see if anyone has any suggestions for where to look and what to test. I have good manuals but am kind of looking for a shortcut here.

Thanks and happy cruisin'!

subzali
06-09-2011, 06:59 PM
Brake booster leaking?

Junk in fuel bowl?

What's the fuel level in the float bowl when it stalls? I understand it's hard to see on an FJ60.

Air Randy
06-09-2011, 07:37 PM
Is it possible that you ran such a rich mixture of methanol that it ate something up in the carb? I know thats why a lot of older rigs can't the stuff.

SteveH
06-10-2011, 06:15 AM
Can you temporarily (or permanently) mount a vacuum gauge in the truck so that you can watch the vacuum under the stalling condition? I wonder if something could be hanging up and causing low vacuum and a stall when you return to idle.

RicardoJM
06-10-2011, 07:04 AM
Bummer about the stalling issue. There are many potential causes, and it would be nice if fortune shines upon you and it is easily addressed. Along those lines, I would recommend you inspect the wiring that provides power to the Idle Cutoff Solenoid. TheBoomBoom had a bad splice in his Hilux which caused intermittent stalling behavior similar to what you have described. I would also recommend you conduct a thorough check for vacuum leaks. These two things may find an easy issue that once addressed fixes the problem.

If you don't find any of the above issues there, the next step would be to tuck into those manuals (and/or get side by side with "correct" 60) and make sure the components and connections for fuel and emissions is what it should be. Followed by conducting the FSM tests on the components. It is time consuming and laborious, but anything less and you could easily spend much more time as you work through issues and finally arrive at the same place. Compared to our early 40s the 60s have more things, but even on our 40s in these situations success is the result of checking each thing.

Presuming all that is done, next I would recommend getting into the carb. With the jet changes, it is possible that some debris (it doesn't take much) made its way into the fuel bowl and is floating around in there causing fuel delivery issues with the idle circuit.

Rzeppa
06-10-2011, 10:25 AM
Brake booster leaking?

Good theory. Except she'll idle fine most of the time just sitting there with the brakes on. And, she can also stall when the brakes are not on, just the parking brake.

Junk in fuel bowl?

I thought of that, especially since I had to access it (twice) to change out the jet. But, when you come to a stop, anything heavier than fuel in the fuel bowl would go forward, away from the jets.

What's the fuel level in the float bowl when it stalls? I understand it's hard to see on an FJ60.

She starts right up instantly after stalling, so there is plenty in there.

Rzeppa
06-10-2011, 10:29 AM
Is it possible that you ran such a rich mixture of methanol that it ate something up in the carb? I know thats why a lot of older rigs can't the stuff.

I was a little worried about that. Basically I went to the gas station across from the emission station, while the gauge was on "E", put in four 12 oz. bottles of Heet, went across the street, passed emissions, then immediately filled up with 15 gallons, so it means I had 8 gallons in there when I put the Heet in, and the full 23 gallons for most of that tank. I refilled again at about halfway down.

The stalling started as soon as I backed the timing to 7 and changed out the jet. It just didn't stop when I put the timing back and put the old jet back, however it did improve quite a bit.

Rzeppa
06-10-2011, 10:31 AM
Can you temporarily (or permanently) mount a vacuum gauge in the truck so that you can watch the vacuum under the stalling condition? I wonder if something could be hanging up and causing low vacuum and a stall when you return to idle.

Yes, I can, and that is an outstanding idea. I have a portable gauge that when I use it in dynamic conditions driving around I just run the hose into the cab through the window.

subzali
06-10-2011, 12:14 PM
Jeff, I had junk floating in my carb that would cause a stall when I was coming off the interstate or up to a stoplight and my rpm would drop to idle. Cleaned it out and it was good to go. It might still be worth a check.

BreckBJ44
06-10-2011, 12:51 PM
I vote junk in the carb... I had the same issue with an 81 40 and an 87 60.

I also second the fuel cut off solenoid. Both of the above rigs would have your exact issue when run on the highway and I would hit an exit ramp. I think it had something to do with heat and resistance in the weak wires to the shutoff. I rewired both and it went away.

Rzeppa
06-11-2011, 12:00 PM
I think the next thing I am going to do is visually inspect as much of the wiring to the solenoid as I can. I will also re-study the section of the manual where it describes the condition(s) under which the power is removed from that solenoid other than turning the switch off - I seem to remember something about deceleration. If that turns up nothing, then I will remove both jet access ports from the front of the bowl and try compressed air in one, coming out the other and vica versa to clear out any potential debris. Then if that doesn't work, I may try hardwiring the solenoid to switched power instead of letting the computer control it.

60wag
06-11-2011, 04:38 PM
There is a vacuum activated switch called the vacuum switch that should be mounted on the driver side fender close to the headlight. I had several of these measure bad. It might cause the "computer" to shut off the idle solenoid at a bad time. Yes, try wiring the idle solenoid to be on with the ignition to see if the stall goes away.

MDH33
06-11-2011, 05:43 PM
In addition to all the good advice already given, don't rule out the EGR. Disconnecting the vacuum line won't have an effect if it is stuck open, which is common. Do a quick test of pulling vacuum on it (by mouth works fine) and see if the diaphragm is moving freely. If it's stuck open you would have exhaust gas dumping into the intake at idle when warm, which would cause a stall. Just something quick to try before you start opening up your carb. ;)

Rzeppa
06-13-2011, 10:00 AM
In addition to all the good advice already given, don't rule out the EGR. Disconnecting the vacuum line won't have an effect if it is stuck open, which is common. Do a quick test of pulling vacuum on it (by mouth works fine) and see if the diaphragm is moving freely. If it's stuck open you would have exhaust gas dumping into the intake at idle when warm, which would cause a stall. Just something quick to try before you start opening up your carb. ;)

I thought I had written this, but always going for the easy stuff first, I disabled the EGR system by disconnecting the hose between the vacuum modulator and the EGR valve and capped it off. It made no difference, so there is one potential cause eliminated.

trucruiser
06-15-2011, 09:22 AM
I was having the same issue and went through a bunch of emission stuff, But for some reason i think i nailed it with a vacuum leak on the manifold (make sure all of the bolts are tight) I also adjusted the valves at the same time and re-timed it. It still does not run quite like i think it should, so my next step will rebuild the carb but i dont have the idle issue anymore.
HTH

Rzeppa
06-15-2011, 10:14 PM
As a reminder, this is an intermittent issue and only manifests when rolling. She will sit there in the driveway and idle all day with no issues. It's really hard to stick your head under the hood and fiddle with stuff while rolling.

So, I did some more diagnostics but have not yet found the root cause or the fix.

Since I have already eliminated the EGR as the culprit, I focused on the idle fuel cut solenoid and the HAC systems this evening. I have already tested the solenoid by turning the key on and then disconnecting and reconnecting the connector at the carb and listening for the clicks. It clicks.

This evening, with the engine running, I tried disconnecting and reconnecting the solenoid. There was very little change in RPMs at all. With the engine running, I re-verified system voltage is present at the connector. From Bruce's suggestion, I tested the vacuum switch. It is not working. It is closed whether vacuum is present or not. It is supposed to open if there is more than about 14" of vacuum. I didn't measure the vacuum, but my NIST-traceable calibrated fingertip said that the hose had plenty of vacuum. It is unclear whether this non-functioning component has anything to do with intermittent stalling at idle, especially since she idles just fine whether the solenoid is plugged in or not.

Next I poked around the HAC system. This is where it gets interesting. I disconnected the vacuum advance on the outer diaphragm of the distributor and immediately noted a marked increase in idle speed. I thought it might be due to the HAC no longer advancing the distributor - hey I can fix that! But when I plugged the end of the hose with my finger, the idle speed went back down again. WTF??? All that should be doing is allowing a small vacuum leak into the manifold and possibly closing the HAC valve. Supposedly the HAC valve is supposed to open at our elevation (above 3930 feet). It lets a small amount if air into the primary, secondary and idle circuits when open, to make for a slightly leaner mixture, and via the secondary diaphragm on the distributor advances the timing by 7.

Thinking I had maybe found the issue, I adjusted the idle back to stock and then drove around the block and promptly stalled at every opportunity. So that wasn't it. After scratching my head for the allotted time and staring under the hood for a while, studying the manual and all that, I cranked the idle speed back up, closed the hood and vowed to post up my observations in the hope of getting pointed in a better direction.

subzali
06-16-2011, 08:15 AM
I'd be surprised if you're pulling more than 14 in. Hg vacuum ever at this altitude.

RicardoJM
06-16-2011, 08:51 AM
...I have already tested the solenoid by turning the key on and then disconnecting and reconnecting the connector at the carb and listening for the clicks. It clicks.
Good news to hear the switch activates when power is applied.:thumb:

This evening, with the engine running, I tried disconnecting and reconnecting the solenoid. There was very little change in RPMs at all.
This is odd. Your results indicate primary circuit is feeding fuel at idle. What RPM was the engine idling at when you did this check? When tuning a carb I want start out at the lowest RPM (500 or less) the engine will run at; to insure it is running off the idle circuit. I would have expected that when power is cut to the solenoid, there would be a very noticeable change.

This evening, with the engine running, I tried disconnecting and reconnecting the solenoid. There was very little change in RPMs at all. With the engine running, I re-verified system voltage is present at the connector. From Bruce's suggestion, I tested the vacuum switch. It is not working. It is closed whether vacuum is present or not. It is supposed to open if there is more than about 14" of vacuum. I didn't measure the vacuum, but my NIST-traceable calibrated fingertip said that the hose had plenty of vacuum. It is unclear whether this non-functioning component has anything to do with intermittent stalling at idle, especially since she idles just fine whether the solenoid is plugged in or not.

If I'm tracking with everything (that is a big IF), this would indicate that when the solenoid is connected to the broken vacuum switch - there is no power to the solenoid. In effect the carb is running w/o the idle circuit and it is consistent with the intermittent issue you are having. At lower RPM feeding fuel from the primary it will idle just fine, but in the varying conditions of driving the vacuum varies enough that sometimes it is not strong enough to keep pulling fuel through the primary circuit - resulting in stalling, whereas as the higher RPM vacuum is sufficient to keep the flow of fuel going.

Easy enough to validate, jump the idle cutoff solenoid to power, drop your RPM back down and go for a test drive, i.e. bypass the vacuum switch. Of course when you turn off the ignition you will have some dieseling because the cutoff is jumped to power.

Rzeppa
06-16-2011, 03:07 PM
This is odd. Your results indicate primary circuit is feeding fuel at idle.

Not necessarily - my results are that (1) power is present at the connector and (2) the solenoid clicks audibly. That doesn't necessarily mean fuel is being fed through the slow circuit. However, among the things I tried a while ago was adjusting the idle mixture screw. It is currently set at 3 turns out. I thought that perhaps things were a little too lean but opening more makes no real difference, whereas closing it up does reduce idle speed.

What RPM was the engine idling at when you did this check?

Around 900. I don't think she will run much below that.

When tuning a carb I want start out at the lowest RPM (500 or less) the engine will run at; to insure it is running off the idle circuit. I would have expected that when power is cut to the solenoid, there would be a very noticeable change.

See above, and yes so would I!

If I'm tracking with everything (that is a big IF), this would indicate that when the solenoid is connected to the broken vacuum switch - there is no power to the solenoid.

There is power to the solenoid. I measured it with a DMM with the engine running and not running.

In effect the carb is running w/o the idle circuit and it is consistent with the intermittent issue you are having. At lower RPM feeding fuel from the primary it will idle just fine, but in the varying conditions of driving the vacuum varies enough that sometimes it is not strong enough to keep pulling fuel through the primary circuit - resulting in stalling, whereas as the higher RPM vacuum is sufficient to keep the flow of fuel going.

It sure seems like the slow circuit isn't getting fuel at times, but as I wrote, plugging and unplugging the solenoid while the engine is running does not seem to make much difference in idle RPM.

Easy enough to validate, jump the idle cutoff solenoid to power, drop your RPM back down and go for a test drive, i.e. bypass the vacuum switch.

60s are not like 40s. The idle solenoid get + power through the ignition just like a 40, but unlike a 40, it gets its ground through the computer. The vacuum switch is not directly connected to the solenoid, it is simply an input to the computer. There are several inputs that make the computer decide whether the idle solenoid should be open or closed. Vacuum or no vacuum is one of them, RPM is another. I am at work and don't have the manual in front of me but it isn't about dieseling - it is about preventing the cat from overheating under certain circumstances.

But the business with the HAC is a real head-scratcher for me. What the heck is up with those observations?

Rzeppa
06-17-2011, 04:54 PM
In my continuing saga of trying determine the root cause of the intermittent stalling at idle, I turned my attention to the Hot Idle Compensation (HIC) system. What it is supposed to do is lean out the mixture as the engine gets hotter. It does this with the temperature-sensitive HIC valve and Hot Air Inlet (HAI) diaphragm.

Below is the table which shows how it is supposed to operate:

Rzeppa
06-17-2011, 04:56 PM
The HIC valve itself is mounted on the underside of the air cleaner housing just above the distributor. As you can see, it is supposed to introduce a deliberate vacuum leak into the intake manifold via the PCV circuit. This is what the plumbing is supposed to look like:

Rzeppa
06-17-2011, 05:07 PM
So I study the plumbing I have. Holy wrong connections batman! Instead of being connected to the PCV circuit, it goes to the port on top of the distributor cap that is normally supposed to connect to the clean side of the air cleaner housing, which ventilates the inside of the distributor cap!

So what is that VCV that is connected to the PCV circuit for? Why does it have that hose connected to itself?

If I knew exactly what that VCV was for I would have a fighting chance of connecting everything back properly. I know the HIC valve is supposed to connect to that PCV circuit. I know the distributor cap is supposed to connect to the clean side of the air cleaner housing. I am not sure where that vacuum line on the right of the VCV connects to at its other end.

Rzeppa
06-17-2011, 05:08 PM
At first I thought that VCV was for the EVAP system. But then I traced the lines to and from the charcoal canister to this VCV:

Rzeppa
06-17-2011, 05:10 PM
Oh, and as a follow-up, I did measure the vacuum at the vacuum switch with the engine running. I only got about 9". Note that this isn't raw manifold vacuum, it is just below the throttle plates so is somewhat less than full manifold vacuum. When I reduced the idle by closing the throttle plate some I got it up to about 12". Certainly not enough to activate it. And makes me wonder if a valve adjustment might be in order...

60wag
06-17-2011, 06:42 PM
The VCV on the passenger side is for the distributor ventilation - not mentioned in the emissions manual if I recall. The other VCV is part of the canister purge system. The HIC circuit doesn't have a VCV in it. The connection to the PCV circuit is just a vacuum source I thought.

Is the HIC atmosphere port just a vent to let the door in the air cleaner housing return to its default position?

MDH33
06-17-2011, 07:17 PM
Jeff, you're welcome to park your 60 next to mine and compare the vacuum spaghetti connections. Mine are stock and properly connected.

Rzeppa
06-17-2011, 10:13 PM
The VCV on the passenger side is for the distributor ventilation - not mentioned in the emissions manual if I recall.

Thanks Bruce! That is good to know! It is not mentioned in my manual either. The distributor in my 78 has a much simpler vent system: Hose to the clean side of the air cleaner housing, check valve so gas fumes don't blow up the distributor, hose to the firewall where there is a filter on the inside as inlet for the distributor venting.

I wonder why they would use a VCV instead of a regular check valve like they do on my 78? In any case, clearly this is plumbed wrong, but will correcting it fix my stalling problem? Doubtful IMHO. I still wanna fix it though.

The other VCV is part of the canister purge system. The HIC circuit doesn't have a VCV in it.

That is what the manual shows. And as I wrote, I traced the lines and figured out what all that was about.

The connection to the PCV circuit is just a vacuum source I thought.

The EVAP system has its own connection to the intake - it is near the top of the carb.

Is the HIC atmosphere port just a vent to let the door in the air cleaner housing return to its default position?

No the HIC has it's own port to the clean side of the air cleaner housing. When open, it bleeds air into the manifold as shown in the table according to the air temperature at the HIC. It appears that the source of temperature for the HIC is from the flow from the HAI. I think...

Again, at the end of the day, I can look at so many things that might be right or wrong with this system, but she used to idle just fine before I dorked around with getting her through emissions. I *thought* I put her back the way she was, but clearly something has still changed. I still haven't tried blowing out the bowl of the carb.

Rzeppa
06-17-2011, 10:16 PM
Jeff, you're welcome to park your 60 next to mine and compare the vacuum spaghetti connections. Mine are stock and properly connected.

Thanks Martin, I may take you up on that. Or if you wanted to just snap a couple of pictures that would be helpful?

Air Randy
06-18-2011, 07:48 AM
Try the "shade tree" carb rebuild. Take the air cleaner off, put a glove on your hand, rev the motor up to about 2,500 rpm, then slam your hand over the bowl of the carb and kill the engine. If you have a little piece of crud in there that got introduced when you changed the jets or added all of the methanol, this could suck it through with the vacuum spike it causes. Nothing to lose by trying and it wont hurt anything.

I did it on my 2F and it fixed a rough idle situation instantly.

Rzeppa
06-19-2011, 08:04 PM
Try the "shade tree" carb rebuild. Take the air cleaner off, put a glove on your hand, rev the motor up to about 2,500 rpm, then slam your hand over the bowl of the carb and kill the engine. If you have a little piece of crud in there that got introduced when you changed the jets or added all of the methanol, this could suck it through with the vacuum spike it causes. Nothing to lose by trying and it wont hurt anything.

I did it on my 2F and it fixed a rough idle situation instantly.

That is a good idea Randy! I am familiar with this, my friends used to call it a Polish carb rebuild :hill:

And it would address the question that I keep finding myself going back to: "What has changed"? I may still take off the jet access ports and blow some compressed air into the bowl though. I really don't want to have to take the air horn off the top to access the bowl, there is just so darn much crap on a 60!

Rzeppa
06-25-2011, 05:27 PM
Still have the problem.

I stopped off at Joe Calleja's because I was nearby, and borrowed his emissions FSM to figure out the correct way to connect the HIC system and the distributor cap ventilation system. I did that right there.

Joe strongly suspected a fault in the emissions computer which might be intermittently ungrounding the idle fuel cut solenoid. I reminded him that he had "repaired" this particular computer and the receipt I got from the PO showed he had charged $300 for it. He said there might still be a problem and that I should take a look at it.

His tech Gary thought there might be an obstruction in the idle circuit passages. I told him of my plan to blow compressed air into the bowl through the jet access ports. He said if it were him, he would remove the idle solenoid and the idle mixture screw and spray carb cleaner though the idle circuit passage.

So I have taken the computer out and examined it under very high magnification. There were no obvious problems but I could see which solder joints Joe had apparently simply reflowed and added more solder, and the flux was still there. They were all for the connector itself. So I removed the excess solder with solder wick, resoldered the joints properly, cleaned the flux and reinstalled the computer. Then, just to be sure I built a pigtail and hardwired the negative connection for the solenoid straight to ground at the computer connector.

That didn't fix the stalling problem, but it completely eliminated the computer as the cause.

Next I tried gloved hand over the carb throat trick.

That didn't fix the stalling problem but at least I tried.

Today, I drove her to the store and a bunch of errands and had no stalling issues at all. This thing is maddeningly intermittent!

Rzeppa
06-26-2011, 04:08 PM
:bump:

So, any helpful ideas fellas?

MDH33
06-26-2011, 05:22 PM
:bump:

So, any helpful ideas fellas?

Hey Jeff, sorry I didn't reply sooner, I was away all last week. If you have time this week, feel free to bring it by and we can park it next to my 60 and do a comparison of emissions gear. If it all checks out, my thought would be to pop the carb off and rebuild it.

BreckBJ44
06-27-2011, 07:12 PM
Good News: I have a spare Emissions computer if you want to plug it in and see if it helps the issue...

Bad News: I am in Vail/Breck until the 5th...

let me know if you want to try it out and I will bring it down with me..

K

Rzeppa
06-28-2011, 11:49 AM
Hey Jeff, sorry I didn't reply sooner, I was away all last week. If you have time this week, feel free to bring it by and we can park it next to my 60 and do a comparison of emissions gear. If it all checks out, my thought would be to pop the carb off and rebuild it.

Visual side-by-side will probably be helpful to verify that I have now got everything plumbed properly. The carb was rebuilt about 2,000 miles ago so it should not need an overhaul, but it is possible that I introduced some crud while changing the jet 2x.

Rzeppa
06-28-2011, 11:51 AM
God News: I have a spare Emissions computer if you want to plug it in and see if it helps the issue...

Bad News: I am in Vail/Breck until the 5th...

let me know if you want to try it out and I will bring it down with me..

K

Thanks Kraig, that might be helpful. I know that I have eliminated the computer's control of the idle fuel cut solenoid, however there are a few other functions that the computer does which might be the culprit.

BreckBJ44
06-28-2011, 01:18 PM
I'll get it out of the shed and bring it back down with me after the weekend...

K

trucruiser
06-29-2011, 11:09 AM
Anxiously awaiting a solution to your problem. please post when you get it nailed down.
Cheers

60wag
06-29-2011, 11:14 AM
Didn't you say that disconnecting the idle solenoid had little effect on the idle? That sounds like something has been adjusted to compensate for the solenoid. That thing should be able to kill the engine at a resonably low idle.

Rzeppa
06-29-2011, 03:04 PM
Anxiously awaiting a solution to your problem. please post when you get it nailed down.
Cheers

I am too! :lmao:

I am pretty close to wits end. I am going to email Robbie in his official capacity as TT Tech Editor and see if he has any additional suggestions. Each remaining course of action seems more and more time-consuming and laborious!

It's gotta be something simple (I hope!). And I have to keep asking myself, what has changed? It used to be fine before I made a couple simple changes to pass smog, then when I un-made those changes the stalling didn't go away!

Rzeppa
06-29-2011, 03:11 PM
Didn't you say that disconnecting the idle solenoid had little effect on the idle? That sounds like something has been adjusted to compensate for the solenoid. That thing should be able to kill the engine at a resonably low idle.

That is right Bruce. I have the idle speed screw set such that the throttle plates are partly open all the time. Sometimes it idles at 1200 RPM when it is like that, other times maybe down to 1000. I know stock is 650 but it won't run that low and never did. When I first got it and it ran great the idle was a little high at about 900 or so. No matter what she won't idle much lower than 900 or so. Which may be related to:

With the relatively low vacuum, the sound this engine makes (very throaty for a non-header stock 2F) and the knowledge that at one point this was a MAF engine I suspect the cam is a long-duration model. MAF used to really push long-duration cams ("RV Grind") back in the day. I doubt that is the root-cause of my problem but it does explain why it won't make 14" of vacuum to actuate the vacuum switch.

I remember Bruce Miller's 2F powered 60 that Mark Whatley built had a long duration cam and idled like crap. Of course that rig had a quadrajet too, which is pretty high flow for a 4.2, even at idle.

Rzeppa
06-29-2011, 03:15 PM
And just to reiterate - the solenoid does click when you unplug it and plug it back in, and I have verified battery voltage is present at the connector when the key is turned whether the engine is running or not. And I have bypassed the computer ground by pigtailing the connector straight to ground at the computer.

60wag
06-29-2011, 05:35 PM
So are you sure you don't have a vac leak? Maybe cap off all of the vac operated devices at the manifold (including the brake booster) and see what kind of vac can be measured at the intake manifold? An idle speed of 1100 would drive me nuts.

Rzeppa
06-30-2011, 10:00 AM
So are you sure you don't have a vac leak? Maybe cap off all of the vac operated devices at the manifold (including the brake booster) and see what kind of vac can be measured at the intake manifold? An idle speed of 1100 would drive me nuts.

Of course I am not 100% sure I don't have an unintentional* vacuum leak. But I have to remember that she ran fine before smog, and all I did was retard the static timing, add some heet, replace the air filter element and change out the primary jet. After smog I put the old jet back in and re-advanced the static timing to exactly where it was, and have now run a couple tanks of fuel through. And this is totally intermittent but only occurs under one condition: When rolling to stop, disengage the clutch and foot off the throttle. If you roll to a stop very gently (slow rate of deceleration) she usually won't die, only when stopping quickly.

*Both the HIC system and the HAC system introduce intentional vacuum leaks. The HIC system introduces air directly into the manifold through the PVC valve tubing, and the HAC introduces air directly into 3 places in the carb: idle, primary and secondary circuits.

A very odd observation I had written about earlier in this thread was that when I remove the vacuum line from the HAC diaphragm of the distributor the idle speed picks up. While it is disconnected, if you plug the end of that line with your finger the idle goes back down. :dunno:

60wag
06-30-2011, 10:41 AM
Maybe you booster is leaking and stopping quickly creates a big enough leak to stall it? Do you have an in cab vac gauge so you can watch it while stepping on the brake pedal?

Rzeppa
06-30-2011, 09:44 PM
Maybe you booster is leaking and stopping quickly creates a big enough leak to stall it? Do you have an in cab vac gauge so you can watch it while stepping on the brake pedal?

Somewhere earlier in this thread Steve Helmreich suggested checking with a gauge and I had replied that I have a portable gauge and a T that I can run from inside the cab. I guess it is easy enough and worth checking, but I haven't done that yet. I appreciate all the suggestions, they are helpful!

I suppose interpretation might be an issue. If it stalls I bet any vacuum would go away in a hurry, right?

And of course having the brake depressed at a dead stop does not make it stall, nor does simply slowing down.

SteveH
07-01-2011, 05:58 AM
Even thought I recommend hooking up a gauge, I think a brake booster leak big enough to kill the engine would create a noticeable sound or other sensation (pedal feel) such that you wouldn't need a gauge - just thinking out loud.

I would also run a test by temporarily disconnecting the HAC valve (mine never seemed to make any difference) and get rid of anything that could be overreacting during this delicate return-to-idle time frame.

Are there any dash pots on the throttle that keep it from snapping shut under decel? This his how my '66 Mustang would stall - when you floored it, and then suddenly backed off, it would snap the throttle shut and die, due to too much gas and no more air. Many later carbs (GM, Ford) had dash pots that prevent the throttle from snapping shut and overfueling the engine. When these dash pots were defective/missing, you'd get an off-throttle stall. I just don't recall if FJ60s have such a device.

Rzeppa
07-01-2011, 08:53 AM
Even thought I recommend hooking up a gauge, I think a brake booster leak big enough to kill the engine would create a noticeable sound or other sensation (pedal feel) such that you wouldn't need a gauge - just thinking out loud.

True. I had a leaky booster in my '76. It never made the engine run any differently, but just made it hard to press the brake pedal enough to stop! Because I didn't know better back in the 1980s, I drove it like that for however many months and ended up burning up exhaust #5. That was an expensive lesson.

I would also run a test by temporarily disconnecting the HAC valve (mine never seemed to make any difference) and get rid of anything that could be overreacting during this delicate return-to-idle time frame.

That's an interesting idea. I *think* the HAC is supposed to always be on when above a certain elevation (about 4,000 feet), and always be off below that. There is actually some hysteresis according to the manual, but at 7,000 feet it should always be on.

Are there any dash pots on the throttle that keep it from snapping shut under decel? This his how my '66 Mustang would stall - when you floored it, and then suddenly backed off, it would snap the throttle shut and die, due to too much gas and no more air. Many later carbs (GM, Ford) had dash pots that prevent the throttle from snapping shut and overfueling the engine. When these dash pots were defective/missing, you'd get an off-throttle stall. I just don't recall if FJ60s have such a device.

What is a dash pot? Nevermind - Wiki to the rescue:

"A dashpot is a mechanical device, a damper which resists motion via viscous friction. The resulting force is proportional to the velocity, but acts in the opposite direction, slowing the motion and absorbing energy. It is commonly used in conjunction with a spring (which acts to resist displacement)."

I don't think so. There are at least 4 vacuum diaphragm actuators on the carb. Choke breaker, AC idle kick up, secondary actuator, and a fourth one I forget what it does (manual isn't in front of me). I have watched the AC idle kick up operate as the compressor cycles on and off.

Instead of disconnecting just the HAC, I wonder what would happen if I disconnected both vacuum advance diaphragms from the distributor and drove around?

SteveH
07-01-2011, 02:41 PM
Since mechanical advance provides (allegedly) 80% of all spark advance, all you should notice with the vacuum advance disconnected is just a bit less power. Go for it.

Rzeppa
07-01-2011, 03:27 PM
Since mechanical advance provides (allegedly) 80% of all spark advance, all you should notice with the vacuum advance disconnected is just a bit less power. Go for it.

I don't know if it is quite that much, but certainly more than half. I know the manual says HAC is 7. I don't know what the spark control advance is. But yeah, I've done that before. When I first got my Jim C. carb for my 71 I still had the stock retard distributor on it so I capped off the ported vacuum on the carb until I could install a non-USA advance distributor. It wasn't bad, but definitely got more kick when I got the proper distributor.

BreckBJ44
07-04-2011, 07:01 PM
The HAC starts to open and allow a second air addition channel to the carb at around 2000 feet. It maxes out and is at full open at 4000 feet so here, the HAC does the same as running with that hose connected to the air cleaner. It does however allow for a richening of the mixture when dropping below 4000 feet which I used to do often in my 87 60. I still would have to do a lean drop idle set If I was staying down there for long...

I will be bringing my whole complete 60 Harness with me when I come back down to town tomorrow night. Let me know a good way to get it to you as I (as always it seems) will not be able to make the meeting due to a work commitment.

Rzeppa
07-05-2011, 10:29 PM
The HAC starts to open and allow a second air addition channel to the carb at around 2000 feet. It maxes out and is at full open at 4000 feet so here, the HAC does the same as running with that hose connected to the air cleaner. It does however allow for a richening of the mixture when dropping below 4000 feet which I used to do often in my 87 60. I still would have to do a lean drop idle set If I was staying down there for long...

I will be bringing my whole complete 60 Harness with me when I come back down to town tomorrow night. Let me know a good way to get it to you as I (as always it seems) will not be able to make the meeting due to a work commitment.

Thanks Kraig. Yeah I studied the manual quite a bit, and the HAC bleeds air into all three carb circuits, primary, secondary and idle. And of course advances the distributor, 7 according to the manual. What I am trying to wrap my brain around is what might (1) intermittently adversely affect either timing or mixture ONLY under the dynamic condition of rolling to a stop AND (2) was something that somehow got buggered up when I changed the jet and timing for smog and somehow didn't get fixed when I put the old jet back in and put the timing right back where it was. I have certainly been keeping (3) in mind: it just came up on its own and had nothing to do with the smog stuff, which is where the majority of these suggestions have been running.

BreckBJ44
07-07-2011, 05:26 PM
I'm back in town if you want to play with that computer. I live downtown but will be heading south tomorrow and over the weekend if you are around.

K

BreckBJ44
07-07-2011, 05:29 PM
One silly question... do you engine brake when this happens? Maybe you are backfeeding pressure somewhere into the system?

I was thinking that if the engine runs a vacuum when running at idle or above, wouldn't engine braking actually put positive pressure into the system if a check valve wasn't working properly? Just an idea.

K

Rzeppa
07-09-2011, 11:16 PM
One silly question... do you engine brake when this happens? Maybe you are backfeeding pressure somewhere into the system?

I was thinking that if the engine runs a vacuum when running at idle or above, wouldn't engine braking actually put positive pressure into the system if a check valve wasn't working properly? Just an idea.

K

No, just the usual way to come to a stop. Shift into neutral around 10 MPH or less and then push down on the clutch pedal while braking to a stop.

I did eliminate one more system today. When I went out driving, I disconnected the HAC distributor advance line and plugged it. I did get one stall, so that ain't it.

trucruiser
07-15-2011, 08:45 AM
Jeff,
Any status updates? Chompin at the bit here.
I picked up a carb, not new or rebuilt but rather low mileage. Im gonna try this out and see if it changes anything. Im still battling the same issue.

Carlos

Rzeppa
07-15-2011, 11:56 AM
Jeff,
Any status updates? Chompin at the bit here.
I picked up a carb, not new or rebuilt but rather low mileage. Im gonna try this out and see if it changes anything. Im still battling the same issue.

Carlos

Hi Carlos, last update was unhooking the HAC vacuum advance line at the distributor diaphragm and plugging the line. It really did not make any difference. I drove around and got one stall.

Two things I haven't tried are (1) removing the solenoid and idle mixture screw and spraying that idle passage with carb cleaner and (2) popping the top off the carb and looking to see if there is any debris in the bowl. I have been avoiding these 2 steps because they are time consumng and kind of a PITA. As I was explaining to Ricardo at the meeting, we can take the top off our '71 carbs in about 15 minutes, maybe even less, but on a darn 60 it takes almost that long just to get the air cleaner cover off! There's a lot more junk on a 60!

We are taking her on a road trip to Ouray next week, but I don't expect any problems other than the intermittent stall when rolling to a stop. She runs great on the road, and once you stop she'll sit there and idle all day.

subzali
07-15-2011, 12:46 PM
for giggles you could try the brake booster line. I know it doesn't make sense, but weirder things have happened.

Rzeppa
07-22-2011, 07:46 PM
for giggles you could try the brake booster line. I know it doesn't make sense, but weirder things have happened.

Of course. I haven't completely discounted vacuum leaks, but I keep asking myself "What has changed?" and also have noted that you do not have to press on the brake for the stalling to occur as you roll along. There was one instance on our road trip where Linda went to change gears and left the clutch depressed for longer than just the gear change without pressing on the brake pedal, and she stalled.

:confused:

There was another instance where we drove through a torrential downpour outside of Gunnison and she bucked and stumbled. At the time I figured it was either a fuel delivery issue or an ignition issue based on the seat of the pants symptoms. After the road dried out and she dried out under the hood (one of the fender splash shields is missing on the distributor side) I surmised that she was leaking HV from the plug wires. I will replace the plug wires and get a new splash shield, and halfway expect this to be my root problem!

trucruiser
07-28-2011, 08:57 AM
Last night I finally got a chance to swap on the other carb i picked up , and it seems to have cleared up my symptoms, It now idles great and during my test drive last night it wouldnt die at stops. Idle is right aroung 700 RPM's and its very smooth.
One observation was my carb mounting nuts were loose, I dont think that was the cause of my problem but im sure it had some effect.

Cheers

Rzeppa
07-28-2011, 12:54 PM
Last night I finally got a chance to swap on the other carb i picked up , and it seems to have cleared up my symptoms, It now idles great and during my test drive last night it wouldnt die at stops. Idle is right aroung 700 RPM's and its very smooth.
One observation was my carb mounting nuts were loose, I dont think that was the cause of my problem but im sure it had some effect.

Cheers

That's good to know. How long did you have your problem? Did it work fine and then suddenly start having problems like mine did? Or have you had this problem a long time and/or it came on gradually?

trucruiser
07-28-2011, 01:34 PM
When I got my 60 it was not running, the PO told me the engine was shot as it had a rod knock (his mechanic said) Turned out to be the smog pump was shot. So i have been gradually resurrecting it, new smog pump as well as some smog equipment. It still would not run quite right until i adjusted the valves, that made a huge difference, I also snugged the manifold bolts at the same time, I got a half turn on them.
After this the truck ran pretty good until i would come to a stop, and then it would die. Some days it would run good and not die at a stop and then suddenly it would do it again. It had me baffled and it would do it randomly when coming to a stop, so hit and miss.
I cant really say its fixed as i havent drove it much since swapping the carb , but my initial test drive last night was different, it drove different and had more power, definitely does not feel like my truck :) in a good way.

Curious drive it some more.

Rzeppa
08-24-2011, 06:26 PM
Well I am still dealing with this issue, but keep working through potential causes and eliminating things one by one. One of the things that occurred to me is that 60s have two vacuum advance diaphragms, one for the spark control and the other for the High Altitude Compensation (HAC) system. The latter is supposed to simply give an extra 7 whenever you are over approximately 4,000 feet elevation, which is everywhere around here. The former is supposed to kick in here and there and is more an emissions thing (the manual says it is a retard).

Anyway, my thinking was that maybe one of these was kicking in when it wasn't supposed to, or not kicking in when it was supposed to. When I smogged this rig I discovered the static advance was set at 17, which is really far for a 60. Robbie thought that maybe the distributor had been installed off by a tooth, but the advance reading I got was from a dial back light, so it really doesn't matter which teeth are engaged with the cam.

When I took the cap off, this is what it looked like - pretty corroded!

60wag
08-24-2011, 07:27 PM
There is a bearing below the stuff shown in the pic for the mechanical advance. It is likely corroded and not moving as it should.

Rzeppa
08-24-2011, 07:39 PM
Okay, so that looks pretty corroded. But remember, this rig runs GREAT at all throttle positions above idle.

So to see what's going on with the diaphragms, I got out my Mity-Vac. Normally I use it for one man brake bleeding, but I made a tube adapter out of two different diameter tubes to go from the Mity-Vac to the little vacuum ports on the diaphragms.

First I hooked it to the inside spark control diaphragm. I squeezed the trigger and nothing happened. I disconnected and thought maybe my tubing had a leak. Nope, one pump up to 10" on the gauge, two pumps up to 20" and holding on the gauge when I put my finger over the hole at the end of the tubing. Try again, same result.

So the spark control diaphragm has a leak and is inoperative.

Next I tried the outside (HAC) diaphragm. This time it held vacuum, but didn't budge the distributor. Not really surprising seeing how corroded the inside of the distributor body is.

So neither vacuum diaphragms are doing anything. Good or bad.

Basically all I have is static and (hopefully) centrifugal advance. I think the centrifugal advance is working because I remember that when I was dorking around with the timing for emissions that it changed with RPMs.

At the end of the day, I don't think the timing is causing my intermittent stalling at idle issue. It will be good to get that working again though, and fortunately I do have a spare used 60 distributor. I just need to give it a good work over to make sure I am not wasting my time if I put it in.

Rzeppa
08-24-2011, 07:47 PM
While I was at it, I replace the plug wires with new OEM from Stevinson. We had a horrible stumbling problem at highway speed when driving through a torrential downpour on a road trip and it went away when we got out of the rain and things dried out. I figured the old, aftermarket wires were old and likely leaky. Odd thing about the new OEM wires is that number 2 and number 5 are straight and all the rest are right angles. Note the Yazaki OEM wires are even numbered!

Rzeppa
08-24-2011, 08:03 PM
So at this point, I am pretty sure I have some kind of obstruction in the idle fuel circuit. When I was up at Joe Callejas, his tech suggested that what he would try is to remove the idle solenoid and the idle mixture screw and spray carb cleaner through that passage. That makes total sense.

Further, when I was at the meeting earlier this month I pulled Robbie aside and asked him and he suggested that he had seen where in some cases, the o-ring on the idle solenoid deteriorated and little pieces of it could clog up that passage. He said he would check for that.

So that's what I did.

I took the idle solenoid out and inspected it. The o-ring was fine. Then I hooked it up and visually observed the operation of the plunger inside. It was working correctly. I sprayed carb cleaner through the port and observed it gushing out where I had removed the idle mixture screw. Then it occurred to me that the passage between the idle mixture screw and the throttle body might be obstructed. So I reamed it out.

Then I put everything back together and went for a test drive.

The good news is, I didn't bugger anything up, she drove great.

The bad news is, the intermittent stall at idle is unchanged.

:(

Rzeppa
09-05-2011, 02:22 PM
Taking advantage of the long weekend and nice weather, I worked some more on my 60. One of the things that a couple of people and I discussed at the Rally was the possibility that there was some kind of intermittent open in the power wiring to the idle fuel cut solenoid.

So I built a couple of pigtails with .250 female disconnects on one end and stripped copper at the other end. I plugged them in to the solenoid connector and then connected the other ends to the battery + terminal and ground respectively. A little risky I know without any fusing but this was just for a quick diagnostic.

When I connected the ground I heard the solenoid clicking it's little head off.

I drove around, and there was no change. Sometimes she'd idle when you roll to a stop, other times she'd stall.

Rzeppa
09-05-2011, 02:24 PM
So the only thing that I haven't checked, out of all the various suggestions I have gotten is to actually take the top of the carb off and see what's going on in the float bowl.

Before I started I snapped a picture in case I couldn't remember how the spaghetti is supposed to reconnect.

Rzeppa
09-05-2011, 02:27 PM
Once I got the top off and looked inside I found a washer from when I reinstalled the old jet after passing emissions! Eureka I think I found the problem! I took the jet out and put the washer on and then reinstalled it.

Rzeppa
09-05-2011, 02:34 PM
After I put everything back together and went for a test drive, I had good news and bad news.

The good news was that I didn't bugger anything up. :)

The bad news was that I didn't fix the problem. :(

I think I am going to pay Robbie to check it out, I am at wits end!

Again, everything was fine until I failed emissions. To pass emissions, I put in a leaner jet, put the timing back to factory 7 static, changed the air cleaner element and added some methanol to the fuel. She ran like crap but passed with flying colors.

After I passed, I filled the tank up with fresh gas, put the old jet back in and put the timing back to 17. I subsequently learned that the reason she needed the 17 was that neither distributor diaphragm was doing any advance, but I am sure that predated the intermittent stall at idle.

After my last test drive and several stalls, I pulled into the driveway and sat while she idled smooth and continuously.

Any new ideas are much appreciated!

MDH33
09-05-2011, 07:23 PM
Any new ideas are much appreciated!


I still think it's the EGR. ;)

subzali
09-05-2011, 08:26 PM
So Jeff, did you replace the distributor with another one that has operational diaphragms? If they're inoperational, maybe they're causing a vacuum leak, rather than everything just being dirty and supposedly seized.

Rzeppa
09-05-2011, 10:41 PM
I still think it's the EGR. ;)

I have already disconnected the EGR so it does not operate.

Rzeppa
09-05-2011, 10:45 PM
So Jeff, did you replace the distributor with another one that has operational diaphragms? If they're inoperational, maybe they're causing a vacuum leak, rather than everything just being dirty and supposedly seized.

No I haven't yet. My take on it is that there is no conceivable reason that a seized vacuum advance on the distributor can make the idle work OK one minute and stall the next. Everything worked fine up until I did a few things to pass smog. Ever since then it has this intermittent stall at idle.

I do plan to replace the dizzy with my spare after I verify that the spare is working properly, but it didn't cause this problem. Likewise with the BVSVs.

MDH33
09-06-2011, 08:19 AM
Jeff, but have you tried disconnecting the tach from the ignitor? I had a weird stumble/hesitation at 2000rpm and after hunting and searching for a reason (I suspected fuel) someone suggested disconnecting the tach. Apparently it's a common problem. Something with the tach causing the ignitor to malfunction. Maybe yours is doing the same but at a lower rpm which causes the stall?

Rzeppa
09-06-2011, 05:30 PM
Jeff, but have you tried disconnecting the tach from the ignitor? I had a weird stumble/hesitation at 2000rpm and after hunting and searching for a reason (I suspected fuel) someone suggested disconnecting the tach. Apparently it's a common problem. Something with the tach causing the ignitor to malfunction. Maybe yours is doing the same but at a lower rpm which causes the stall?

Wow, that is certainly among the more esoteric things I have heard. It stands to reason that the tach might give some input to the emissions computer, along with the speedo, but I thought the ignitor was just power, ground and the signal from the magnetic pickup in the distributor.

I'll have to look into that. Thanks Martin.

MDH33
09-07-2011, 02:14 PM
Wow, that is certainly among the more esoteric things I have heard. It stands to reason that the tach might give some input to the emissions computer, along with the speedo, but I thought the ignitor was just power, ground and the signal from the magnetic pickup in the distributor.

I'll have to look into that. Thanks Martin.

Easy enough to test. Just unplug the connector between the tach and ignitor and drive it around to see what happens. On mine, when the tach would hit 2000 rpm, it seemed like power to the coil was cut momentarily which caused the stumble.

Rzeppa
10-06-2011, 01:35 PM
Easy enough to test. Just unplug the connector between the tach and ignitor and drive it around to see what happens. On mine, when the tach would hit 2000 rpm, it seemed like power to the coil was cut momentarily which caused the stumble.

Where is this connector? And when it starts to stall, all I have to do is goose the throttle - would that still be electrical/ignition? Doesn't that seem more like an issue with the idle circuit fuel delivery?

Rzeppa
10-06-2011, 01:43 PM
I was chatting with Mike Simpson last night after the meeting and I recalled that I hadn't posted up the latest info.

I spoke with Robbie on the phone about this a few weeks ago, and while we both figuratively scratched our heads as I described all my observations. Then he had an interesting theory. He thought that perhaps, if the distributor was that rusty, maybe the centrifugal advance was sticking intermittently?

So the next weekend, I took my spare distributor out and verified that both diaphragms operated when I applied vacuum with my Mit-T-Vac anc that the shaft rotated smoothly. I used my big ol' nut socket on the big ol' nut to rotate the crank to TDC for a good reference point, took the old distributor out and put the new one in. I set the static timing at 11 instead of the 17 that it had been.

Well, she ran absolutely great, but when driving around she still stalls sometimes when you put the clutch in.

Rzeppa
10-27-2011, 09:57 AM
Here's a new data point:

On the spooky night run, I had no issues whatsoever going uphill, however she absolutely would not idle at all when pointed downhill. I peeked inside my spare carb and can't really tell what might be different when pointed uphill versus downhill...anyone have any ideas?

MDH33
10-27-2011, 10:48 AM
Here's a new data point:

On the spooky night run, I had no issues whatsoever going uphill, however she absolutely would not idle at all when pointed downhill. I peeked inside my spare carb and can't really tell what might be different when pointed uphill versus downhill...anyone have any ideas?

Probably not an uphill vs downhill thing, but more likely you're off the gas pedal going downhill. Really sounds like a carb adjustment thing to me. Maybe the butterfly is closed all the way when you're off the gas rather than being slightly open like it should be. Have you taken the carb off to inspect all that and the linkage, etc?

Rzeppa
10-27-2011, 10:53 AM
Probably not an uphill vs downhill thing, but more likely you're off the gas pedal going downhill. Really sounds like a carb adjustment thing to me. Maybe the butterfly is closed all the way when you're off the gas rather than being slightly open like it should be. Have you taken the carb off to inspect all that and the linkage, etc?

I could take my foot off the throttle pedal while going uphill and still keep going. Whenever I was pointed downhill it would stall every time I put the clutch in.

Does anyone know exactly where the fuel for the idle circuit is drawn from? I am wondering if it is from the top of the fuel (as opposed to the bottom where the primary and secondary jets are). If it is in the top rear of the bowl, maybe my float is a little too low?

MDH33
10-27-2011, 10:58 AM
If the float was too low/high, you could see evidence in the sight glass I would think. Is it always in the middle?

Rzeppa
10-27-2011, 11:03 AM
If the float was too low/high, you could see evidence in the sight glass I would think. Is it always in the middle?

I never really thought to check until just now kind of thinking about the uphill/downhill business. Since she runs GREAT at all throttle settings above idle it just wasn't something I thought to check. Normally I look at the sight glass on a rig that seems to be having fuel delivery issues (vapor lock, fuel pump, etc.)

But when you take the top off a carb and take the idle solenoid off, there is one passage that goes down to the mixture screw, and then from there to the throttle body just below the throttle plate. So I was wondering where the fuel comes from that goes to the idle solenoid (upstream)? It must come from the top rear of the float bowl, right?

:confused:

trucruiser
11-01-2011, 11:13 AM
Jeff,
Im still convinced its your carb, Get a rebuild or another and I think your head scratching will be over. I went through this same thing until I popped a new to me carb on and it hasnt died since.

Rzeppa
11-01-2011, 04:33 PM
Jeff,
Im still convinced its your carb, Get a rebuild or another and I think your head scratching will be over. I went through this same thing until I popped a new to me carb on and it hasnt died since.

Well, I certainly agree that it is most likely the carb! The fact is, this carb was rebuilt only a few thousand miles ago, and everything was fine until I changed out the primary jet to pass emissions. I put the old jet back in, but it just has this weird thing where it wants to die when you are either braking or pointed downhill. I wonder if I buggered the float level when I changed the jet? I need to take a peek at the sight glass.

Rzeppa
11-03-2011, 06:50 PM
This evening I got around to peeking into the sight glass and didn't see any fuel! Since modern gasoline is transparent, it is pretty hard to use the sight glass these days, but I am pretty sure the level is below the sight glass.

So methinks I somehow buggered the float when I changed out the jet and need to get back in there and raise the level.

I was looking at the float on my spare carb and it *looks like* I should bend the little doo dad (tech term) downward to raise the float level, right?

RicardoJM
11-03-2011, 07:00 PM
...
I was looking at the float on my spare carb and it *looks like* I should bend the little doo dad (tech term) downward to raise the float level, right?...
Yuppers.

MDH33
11-03-2011, 07:26 PM
I was looking at the float on my spare carb and it *looks like* I should bend the little doo dad (tech term) downward to raise the float level, right?

I think you're supposed to bend the Two doo-dads to either side of the center one to adjust float height. I don't have one in front of me to reference though. There's even a SST for gauging the height. I just made one out of a junk-mail credit card. Works great.

Rzeppa
11-03-2011, 09:25 PM
OK, there's only one doo dad. It is a tab in the sheet metal of the frame that holds the float, and when the float goes upward it presses against the needle valve to close it. Tomorrow I will go take a picture of what I'm talking about.

rover67
11-04-2011, 06:59 AM
that's the doodad you bend to adjust what level the valve closes at. bent it down towards the float to raise the level of fuel. usually there is a spec for float height when you turn the carb upside down and the float rests with its weight against the needle valve. also make sure your float dosent have fuel in it, sometimes they leak then they don't float right.

Uncle Ben
11-04-2011, 07:09 AM
http://media.photobucket.com/image/adjusting%20float%20level%20in%20aisin%20carb/pacapo/Aisin%2520Carb/Aisin2.jpg

RicardoJM
11-04-2011, 07:11 AM
Martin and Marco are correct, there are side adjusting tabs and a center. All three are used to set the full range of motion for the float. Here is a picture, the side tabs controls how "low" the float drops and the center tab controls how "hight" the float rises.

http://www.risingsun4x4club.org/uploads/ricardojm/Carb/w_float001.jpg

Rzeppa
11-04-2011, 09:43 AM
also make sure your float dosent have fuel in it, sometimes they leak then they don't float right.

Oh you know what? I need to check that too! That happened to my lawnmower this past summer and it kept flooding. Except I just thought of something - I don't have a flooding problem, it looks like the fuel level is too low.

Rzeppa
11-04-2011, 09:46 AM
http://media.photobucket.com/image/adjusting%20float%20level%20in%20aisin%20carb/pacapo/Aisin%2520Carb/Aisin2.jpg

Thanks for that link Kevin! My Haynes doesn't show that spec.

I still wonder how I buggered it up just from changing out the jet through the port in the front.

I have noticed that the rod that the float pivots on doesn't have anything to keep it from sliding one way or the other. Maybe the carb casting is what holds it in place?

subzali
11-17-2011, 07:19 AM
Nothing to add really, except a link to a guy on MUD who is having trouble with his FJ40 stalling on downhills:
http://forum.ih8mud.com/40-55-series-tech/531106-going-aisin-details-details-details-3.html#post7108885

Rzeppa
11-17-2011, 10:27 AM
Thanks Matt! I just posted up there. It sure looks like that guy has a similar symptom.

Hulk
11-17-2011, 10:37 PM
I don't have anything to add, but I am posting this diagram to the RS website just in case photobucket goes kaput someday in the future.

subzali
11-18-2011, 07:30 AM
So that guy on MUD had an extra o-ring on his needle valve. So not sure if that's the same problem you have Jeff. Probably not. :(

Rzeppa
11-18-2011, 12:27 PM
I don't have anything to add, but I am posting this diagram to the RS website just in case photobucket goes kaput someday in the future.

Cool! I saved a local copy as well.

Rzeppa
11-18-2011, 12:29 PM
So that guy on MUD had an extra o-ring on his needle valve. So not sure if that's the same problem you have Jeff. Probably not. :(

Yeah, I saw that. I also got replies from both Jim Chenoweth and Charlie (Pin Head). I used to know Pin Head from 10-12 years ago when both of us used to hang out on the CCOT board. Jim says that the idle circuit gets fuel from behind the main jet, so that blows my theory that it comes from the top. I still need to set some time aside to pull the top off the carb again, and this time check the float adjustment. I have just never heard of a float going out of adjustment once it's set, it is so darn simple!

Rzeppa
01-29-2012, 03:31 PM
Yeah, I saw that. I also got replies from both Jim Chenoweth and Charlie (Pin Head). I used to know Pin Head from 10-12 years ago when both of us used to hang out on the CCOT board. Jim says that the idle circuit gets fuel from behind the main jet, so that blows my theory that it comes from the top. I still need to set some time aside to pull the top off the carb again, and this time check the float adjustment. I have just never heard of a float going out of adjustment once it's set, it is so darn simple!

I took the carb apart again yesterday and checked the float adjustment. It was exactly 7mm if you include the gasket. Since the instructions said 7mm to the casting, I bumped it one mm, but when I put everything back together it didn't make a lick of difference. The fuel level is still well below the bottom of the sight glass. Not to mention I seem to have lost a rubber washer. :rant: :mad:

Rzeppa
01-29-2012, 03:32 PM
Here's a good look inside the bowl. You can see the fuel level is way too low. You can also see how clean it is. The specks you see in the bowl are discolorations on the surface, they are not loose objects.

Rzeppa
01-29-2012, 03:34 PM
Here's the rubber washer I lost one of, and where (I think) it goes. Notice the missing one over there on the other barrel. What does this do? What are those passages for?

Rzeppa
01-29-2012, 03:36 PM
Here is my spare carb I have on my bench I use for practice and understanding stuff. Even though it came off a 60, it does not have those two passages, they are closed off.

Rzeppa
01-29-2012, 10:39 PM
Update: Jim C. says on Mud that the rubber washers are for the HAC system, and since the HAC should always be on at our elevation, missing one won't make any difference.

Rzeppa
02-02-2012, 08:24 PM
So if the float is adjusted properly, what else might cause the fuel level to be too low in the bowl?

rover67
02-02-2012, 10:55 PM
Man, no idea...

If the float was full of fuel it's sit heavy...

maybe it is full of helium?


But seriously, maybe it is the wrong float? I am at a loss... Try forcing the fuel level up by adjusting the float way high and see what happens... surely you can force it up by adjusting the float way high right?

RicardoJM
02-03-2012, 06:02 AM
I'm in agreement with Marco. At this point you can can consistently replicate the issue by pointing downhill. Adjust the float (don't worry about the FSM setting) to see if it can make the issue cease. If it does, there are likely other undesired effects from the float being out from spec - but you now have some insight into what conditions are needed and can dig further into why those conditions do not exist.

PhatFJ
02-03-2012, 06:26 AM
Jeff, I went through this EXACT same thing on my 1975 and for the life of me, I could not find the answer. Mine would drain to the same location, the excelerator pump would still have fuel in it so I would pump it with choke on and it would start every time. I did not have the stalling issue, mine would not idle without running into the primary. So after about the fifth time pulling the thing out to see if I could find the problem, I decided to put everything back to where it was before I rebuilt it, while doing this I did a blow test through the idle jets just to check for restrictions and guess what, the main low speed jet that I was taking out (factory spec) was more restricted than the one I was putting back in (the old one) it had the restrictor at the bottom of the jet opened up or removed. I put the old / larger idle jet back in and the problem went away, I could adjust the idle back down to 650 - 700 rpm and it was fine. In conclusion, I could only determine that it was the ISKY cam that the PO had installed, reducing the idle manifold vacuum (which was around 11 inhg) there was no leak in the intake or exhaust... Why am I telling you all this? All I can say, it is not always the logical answer that solves the problem. My problem was in the idle circuit and had to have a low speed idle restrictor virtually removed but it worked.. Good luck!! By the way, the carb bowl still leaked down to where yours is when it sat for a few hours, never did find out where the fuel was going...

Rzeppa
03-15-2012, 01:51 PM
Update: I am having Jim Chenoweth build me a carb. He's going to send it to me and I'm going to then send him my old one. He's certain he will be able to figure out what's going on with my old one. I still drive this rig just about every day.

Brian, I am pretty sure that this 2F has a long duration cam in it. It was a MAF motor and they are well-known for promoting their "RV" grind cams. It has a deep throaty growl I have never heard from a 2F with stock exhaust and have great midrange power. It also only makes around 11 inches of vacuum at 7k feet elevation.

Rzeppa
04-30-2012, 07:32 PM
I got my Jim Chenoweth carb on Thursday and installed it this afternoon (leaving for Moab in the morning, talk about cutting it close!). All I can say is the man knows what he's doing. Runs perfectly, just like the factory intended, problem completely solved. I'll be sending the old one back to him for a post-mortem.

:cheers:

PabloCruise
05-01-2012, 06:34 AM
I got my Jim Chenoweth carb on Thursday and installed it this afternoon (leaving for Moab in the morning, talk about cutting it close!). All I can say is the man knows what he's doing. Runs perfectly, just like the factory intended, problem completely solved. I'll be sending the old one back to him for a post-mortem.

:cheers:

Great that all is well!

I am really interested in Jim's assessment of what was going on with your carb.

SteveH
05-01-2012, 11:39 AM
You must be relieved!

Rzeppa
05-07-2012, 12:51 PM
Great that all is well!

I am really interested in Jim's assessment of what was going on with your carb.

I am too! I just got back from Moab yesterday, so I haven't sent the old one back to him. Do that sometime this week.

Rzeppa
05-07-2012, 12:56 PM
You must be relieved!

I would be if I didn't have a blown head gasket...:rant::(

Made it just past mile marker 3, you could see the rabbit valley exit sign off in the distance. The rig's at Hugh's shop in GJ, he's going to fix it for me and I'll go pick it up whenever it's done, hopefully by next weekend.

I got to drive Marco's 60 to lead Chicken Corner on Thursday, which I was supposed to lead anyway, then rode shotgun with Daniel on Fins on Friday and rode shotgun with Tim on Wipeout on Saturday. Twas fun, but would have nice to have had my own wheels...

Dave Kaiser gave me a ride home. Thank you everyone!

:risingsun

SteveH
05-08-2012, 07:05 AM
Poor guy - hang in there! You now have stories to tell (more, anyway).

PabloCruise
05-09-2012, 12:11 PM
I would be if I didn't have a blown head gasket...:rant::(

Made it just past mile marker 3, you could see the rabbit valley exit sign off in the distance. The rig's at Hugh's shop in GJ, he's going to fix it for me and I'll go pick it up whenever it's done, hopefully by next weekend.

I got to drive Marco's 60 to lead Chicken Corner on Thursday, which I was supposed to lead anyway, then rode shotgun with Daniel on Fins on Friday and rode shotgun with Tim on Wipeout on Saturday. Twas fun, but would have nice to have had my own wheels...

Dave Kaiser gave me a ride home. Thank you everyone!

:risingsun

Serious bummer! :(

subzali
05-10-2012, 10:25 AM
Wow, Jeff! What did you do to the Cruiser gods so that they put these dampers on your Cruise Moab vacations? Did it let go suddenly, did you peg the "H"?

Rzeppa
05-10-2012, 11:17 AM
Wow, Jeff! What did you do to the Cruiser gods so that they put these dampers on your Cruise Moab vacations? Did it let go suddenly, did you peg the "H"?

It was pretty sudden. The PO had installed an aftermarket temp gauge in one of the spots on the t-stat housing where one of the BVSVs normally goes, plus the factory sender in the back of the head still works. I always monitor my instrumentation pretty regularly, and saw both gauges start climbing way faster than normal for just pulling a long hill. This rig normally runs cool as a cucumber and I've never seen the aftermarket gauge go higher than about 200F.

So I immediately pulled over and shut it down. I popped the hood and saw where the rad cap had spattered a little and the overflow tank was full and had a little spattering coming out the cap. The hoses were all fine. I let her sit for about 15 minutes and started it back up, thinking that running the cooler stuff that had been in the radiator through would help. But instead both gauges climbed up to where they had been, plus I got a gigantic cloud of white smoke out of the tailpipe. So I shut it back down, got out and then noticed a great big puddle of coolant....under the muffler!

So the water jacket's talkin' to one or more cylinders. I knew then I wasn't going anywhere under my own power except on to a trailer. That's when Trevor (Isotel I think?) from Colorado Land Cruisers pulled over with his trailered trail rig, and Jeff Zettl stopped too. Trevor pulled his trail rig off and took me and my rig to Safari Ltd.

They got the head off yesterday. It wasn't obviously cracked and it's been sent off to the machine shop to get magnafluxed and if it isn't cracked then they'll deck it flat and send it back.

They said cylinder #6 looks like it got really hot at some point, and is blued, and that the top of the piston looks like it got really hot. They were going to send me some pictures but I haven't seen them yet. I think I know what that was about; when I was dorking around with the stalling issue I basically went through all the emissions subsystems and discovered that the HIC system and the distributor cap vents were cross connected. The HIC pulls from a T fitting on the PCV and the PCV bungs to the manifold at the rear, so it basically had a vacuum leak at the rear of the manifold for however many thousands of miles until I corrected it last summer. That would make for an overly lean mixture in the rear of the intake and make for high combustion temps. I'm glad it didn't burn up the exhaust valve.

SteveH
05-10-2012, 09:04 PM
Jeff - good catch on seeing the gauges and stopping before a total meltdown! I hope the head job from here on out is routine.

PabloCruise
05-11-2012, 12:19 PM
Did you get carb off to Jim?

PabloCruise
06-27-2012, 01:49 PM
Any updates on this?

Rzeppa
06-28-2012, 11:40 AM
Yeah, here it is:

Date: Jun 20, 2012 5:58 AM

Jeff, the root cause of failure in the idle circuit was the use of RTV
gasket shmoo on the bakelite insulator. The RTV sgueezed into the
idle passage just enough to restrict flow & prevent idling. RTV
swells & softens in the presence of gasoline, so it may have been OK
for the first day, but would have gotten worse over time.

Thanks,
Jim Chenoweth
TLC Performance
Lancaster, Ohio, USA

Marcy's Automotive in Evergreen did the carb rebuild for the PO. He took it there because it had failed emissions and they were listed on the "official" list of "approved" shops they give you when you fail. So not only did they charge him something like $700, they buggered it up!

Jacket
06-28-2012, 12:12 PM
Wow. Glad that the guru was able to diagnose it finally.

PabloCruise
07-02-2012, 12:32 PM
Wow...

Talk about devil in the details!