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ttubb
08-16-2010, 10:31 AM
On the Triple Bypass run this weekend, Bob (40Zen) was having vapor lock issues. I mentioned to him that my 78 FJ-40 had been converted to a 60 Series fuel pump and the recirc line went from the fuel pump back to the tank, versus from the carb back to the fuel pump. Below are photos first of Bob's stock fuel system (two lines to the carb - supply/return) then my 60 series set-up (single fuel line to carb - supply only). I have NEVER had a vaporlock with this rig (I live at 10,000 feet and wheel uphill from here).
First two are Bob's stock rig, second three are my set-up. I think there is a spacer needed between the pump and the block on the 60 set-up.
Hope this helps someone. Terry

Air Randy
08-16-2010, 11:32 AM
I have a stock FJ40 setup on my 74 using the pressure/return lines from the carb and a stock mechanical fuel pump. I've never had a vapor lock issue either and we wheeled at or above 11K to 12K feet on the 40's only run when a number of other rigs did have issues.

I do have an HEI distributor, I ditched the stock exhaust manifold and installed a header, and I have a liquid heat riser installed on the bottom of my intake manifold.

I believe the liquid heat riser makes the biggest difference. Yes, it helps the rig run better in the winter by warming the base of the intake manifold, but it also keeps the manifold base cooler by ensuring it never gets any warmer than the engine water temp of around 180 degrees.

I guess it's possible that running that different fuel setup helps by increasing the fuel pressure inside the carb to help prevent the fuel vaporizing as easily.

nattybumppo
08-16-2010, 11:40 AM
I have the stock set-up in my 1977 40, emissions gear and everything, and have had no vaporlock issues this summer either. Knock on wood. My 60 on the other hand...

SteveH
08-16-2010, 12:45 PM
Gasohol (now unavoidable) has always caused vapor lock in my stock 1978 '40. My current 'final solution' is a Carter motor type (not vibrator) electric fuel pump mounted ahead of the factory pump, and about 6" lower. It has worked well. My '76 FJ55 was so bad with vapor locking that it left me stranded - first time any 'cruiser did that. I installed a Carter pump at the tank and eliminated the OEM pump - completely fixed it. FJ60-style systems have proven less troublesome across the board than the earlier stuff, for me.

I am no fan of electric fuel pumps (especially Holley junk), but I can't have a vehicle that threatens to kill me by stalling 45 seconds after starting the engine from a hot/parked condition. And yes, I have replaced all the OEM pumps with OEM pumps time and again to no avail. Cursed? Perhaps. But, an electric pump, mounted low and as close to the tank as possible, will save the day.

MDH33
08-16-2010, 07:36 PM
Gasohol (now unavoidable) has always caused vapor lock in my stock 1978 '40.

That's my current theory. I vapor locked on the 40's Run when I cheaped out and put ethanol 85 octane in. When I've run 90+, no problems. Maybe I should look for some Aviation fuel for high elevation runs. :hill:

subzali
08-16-2010, 07:55 PM
FWIW, I've never had any vapor locking problems in the 5+ years I've had my FJ40. I always run 85 octane. I have done everything from run over Pearl Pass, Argentine Pass (13+,000 ft), Mosquito Pass (13+,000 ft), Red Cone, Radical Hill, Red Elephant Hill (steep inclines), as well as run around Denver stop-and-go traffic in the middle of summer heat. It's a stock 10/76 Federal spec. (1977 model year) FJ40 (with no cooling fan), with some of the smog components removed (basically only the air rail and smog pump), and my carburetor is a 9/77-12/78 Federal spec. carb, and my jet settings look stock for '78 from what I have researched.

I'm just saying that it seems reasonable to me that the stock setup shouldn't have vapor locking issues, but if you've tried everything else in the book then maybe you need to look into other options to fix it.

Okay, there's my two cents. I'll get off my high horse now.

MDH33
08-16-2010, 11:38 PM
Mine isn't stock: '77 2F, '69 carb, header, non-usa vacuum advance distributor, no smog gear. So maybe that has something to do with it. not really sure, but it has only happened a couple of times and I always get home eventually. :hill:

PabloCruise
08-17-2010, 07:32 AM
When I lived down in New Mexico I would get occasional vapor lock. A mechanic said that an old trucker trick is to put a quart of ATF in with a tank and that would help with the vapor lock.

I tried it, it worked.

FJ40zen
08-17-2010, 10:55 PM
When I lived down in New Mexico I would get occasional vapor lock. A mechanic said that an old trucker trick is to put a quart of ATF in with a tank and that would help with the vapor lock.

I tried it, it worked.

Cough, Cough! Bet that smelled a little also. ;)

Thanks for the many ideas. I have a NOS pump on there from a few months after I got the cruiser. That didn't work. I am going to try Terry's suggestion first, since the higher octane does not really work in my situation. I have tried that several times before and it makes a little difference, not not enough. I really don't see why I need a return line at all. I definitely know that fuel delivery to the carb is at best - weak, but only when hot. I never have the problem in cooler months.

cbmontgo
06-29-2011, 02:28 PM
I am reviving an old thread here...

I have a '76 FJ40 with a 100% stock setup. I rebuilt the carb last winter and put a brand new OEM fuel pump in last summer.

She runs great, but I was up in Pike National Forest last week and stopped with the kids for about 15 minutes and she vapor locked for about 30 minutes before cooling enough to restart.

I am thinking that the electric fuel pump may be a good idea from what others have told me. Any particular make/model/flow rate/head pressure that you'd recommend?

Also, does higher octane fuel REALLY help?

Rzeppa
06-29-2011, 04:22 PM
I am reviving an old thread here...

I have a '76 FJ40 with a 100% stock setup. I rebuilt the carb last winter and put a brand new OEM fuel pump in last summer.

If it is really 100% stock, how long was the under hood cooling fan running when you stopped?

She runs great, but I was up in Pike National Forest last week and stopped with the kids for about 15 minutes and she vapor locked for about 30 minutes before cooling enough to restart.

I am thinking that the electric fuel pump may be a good idea from what others have told me. Any particular make/model/flow rate/head pressure that you'd recommend?

Make sure you regulate down to about 7 PSI! My daughter's 60 had an electric that made the float bowl needle stick closed intermittently because it put out enough pressure for FI! If your setup is totally stock that shouldn't be as much of an issue because it recirculates, but still...

Also, does higher octane fuel REALLY help?

I doubt it. I just wish they'd stop putting so much darn EtOH into our gas! That is a contributor!

cbmontgo
06-29-2011, 04:31 PM
Thanks.

Mine is the year prior to the carb fan unfortunately (it is a May 1976 build). I have considered installing one.

SteveH
06-29-2011, 05:53 PM
I'm still fighting vapor lock on my '78 while driving down (say, I-25). I have an (apparently) weak Carter elec fuel pump and an OEM pump in series. I may rip it all out and use only an electric pump. Converting to an FJ60 pump is another option I hadn't considered.

I a working OEM electric carb fan that runs for 25 min. after you shut off the engine, but mine is so bad it no longer just vapor locks after parking. I may try a higher-output Carter pump (supposedly puts out 8 psi, rather than 6).

My 1980 FJ40 seems to never vapor lock, but it has headers, and I suspect they remove a lot of the heat that would be boiling the carb.

ttubb
06-29-2011, 06:15 PM
My 1980 FJ40 seems to never vapor lock, but it has headers, and I suspect they remove a lot of the heat that would be boiling the carb.

Steve, my 78 does NOT have the fan (removed) and does have the tuned headers. I am at 9800 feet in Crested Butte and go up from here. I have never had a vapor lock. I do think the headers make a huge difference in keeping the heat away from the carb. Again, I am running a 60 series pump on a stock carb. I do usually use premium fuel since I run the timing at 13 degrees, however I don't know if that makes a difference or not with vapor locking. Terry

SteveH
06-30-2011, 10:03 AM
Terry - thanks for the info. I drove my 1980 FJ today (it's going to be very hot) to see if it would choke. It sounds like a 60 series pump may make sense to try. I have tried several OEM pumps and rebuilt my own, and none have worked well. I cannot entirely explain that...

subzali
06-30-2011, 10:13 AM
Hm, my '77 FJ40 with no carb cooling fan, stock intake/exhaust, stock fuel pump, stock fuel lines, stock carb (well, it's a '78 carb, but jetted stock for '78), running 85 octane always. Never vapor locked.

Sorry, can't really help with reasons why or why not. I think I have my timing set around 10-12 degrees BTDC, but it's been a while so I don't remember exactly.

Rzeppa
06-30-2011, 10:40 AM
Thanks.

Mine is the year prior to the carb fan unfortunately (it is a May 1976 build). I have considered installing one.

My 4/76 FJ40 had the fan...

It was mounted out in the corner by the headlight instead of on the fenderwell next to the brake master like on later units.

cbmontgo
06-30-2011, 10:43 AM
My 4/76 FJ40 had the fan...

It was mounted out in the corner by the headlight instead of on the fenderwell next to the brake master like on later units.

Interesting. Got any pics of it?

Rzeppa
06-30-2011, 10:48 AM
I think one of the biggest heat-producers is the EGR reactor. Obviously most headers don't provide for EGR so that is removed or disconnected in most header applications.

Besides the fan and a strong fuel pump, one of the most effective vapor-lock preventives is the fuel recirculation system, at least while the engine is running. When first introduced the recirculation was at the bowl, after that it was at the pump itself. The former might be more effective at keeping the fuel cooler, because it keep the flow going in the pipes that run over the top/front of the block and valve cover. In any case, what it does is keep drawing cool fuel from the tank, deliver what is needed to the carb and whatever isn't needed is cycled back into the tank.

subzali
06-30-2011, 11:03 AM
Jeff, is your '76 a CA emissions-spec FJ40? I don't believe carb cooling fans became standard on Federal emissions-spec FJ40s until '79 or so.

Rzeppa
06-30-2011, 11:10 AM
Interesting. Got any pics of it?

No, I don't remember that it ever came on and I needed the real estate to mount my second battery when I added a big stereo in 1986. I found a picture of another one here:

http://lh5.ggpht.com/-Ve-4QXpgaes/TNjMkQZTwYI/AAAAAAAABY0/sVkqNScSspM/2f%252520Engine.jpg

This was from a thread here on a rig for sale last November:

http://www.risingsun4x4club.org/forum2/showthread.php?t=14561

Rzeppa
06-30-2011, 11:11 AM
Jeff, is your '76 a CA emissions-spec FJ40? I don't believe carb cooling fans became standard on Federal emissions-spec FJ40s until '79 or so.

Yes, Kalifornia spec.

cbmontgo
06-30-2011, 12:48 PM
Thanks for the pic, Jeff. Mine is a Federal spec, so I guess that might explain why it has no fan. These little oddities always crack me up how the FJ40 changes from year to year and region to region.

Wonder if mine is pre-wired to accept the fan?

subzali
06-30-2011, 01:04 PM
My 10/76 Federal spec FJ40 isn't pre-wired for the fan, so I doubt yours is either.

cbmontgo
06-30-2011, 02:48 PM
My 10/76 Federal spec FJ40 isn't pre-wired for the fan, so I doubt yours is either.

That is too bad. I'd like to have had the plug and play option.

wesintl
06-30-2011, 03:33 PM
I thought my 10\75 fed had the plug but alas I can't remember and it's no where near me.

The good thing is you can easily mount an oem fan and just wire it up for a rocker switch which is better anyway.

Rzeppa
07-01-2011, 11:01 AM
I just re-checked the all images from that 40 for sale and it is a 76 unless the hard top is off another rig. It has the oval bezel so it has to be pre-79, but the rear side windows do not have the flip-out vents which were introduced in 8/76 (one month before the 77 model year) and it has the plate style spare carrier instead of the tube style which was also introduced in 77. It has the early non-full electronic ignitor which was only found on the 76 and 77 model years. It said the engine was out of a 1980 but the distributor is points type and has no cap vents so it must be from the 76.

FJ40zen
07-07-2011, 04:56 PM
I now have a Carter 4070 pump in mine. I cannot wait to test it all out on hot days. I need to finish my bodywork and paint before that happens. I figure that if it dies, I will leave the key on until it pumps fuel back into the carb unless there will be some great pressure keeping it from pushing the fuel from the tank. My fan burned up last year...:mad:


I am reviving an old thread here...

I have a '76 FJ40 with a 100% stock setup. I rebuilt the carb last winter and put a brand new OEM fuel pump in last summer.

She runs great, but I was up in Pike National Forest last week and stopped with the kids for about 15 minutes and she vapor locked for about 30 minutes before cooling enough to restart.

I am thinking that the electric fuel pump may be a good idea from what others have told me. Any particular make/model/flow rate/head pressure that you'd recommend?

Also, does higher octane fuel REALLY help?

Phrog
07-07-2011, 05:35 PM
The picture above - engine with fan - is from my 40 (I bought
it Nov. 2010). It is a 1976, but the block (and block only,
as far as I can tell) is from a 1980. The emissions, distributor,
carb, etc. all seem to be original 1976.

I don't know why a PO installed the carb cooling fan.
The fan has never run since I've had it. Of course, that might be
because it's not wired correctly...I'll have to check that out.

-Phrog

Rzeppa
07-15-2011, 11:56 AM
The picture above - engine with fan - is from my 40 (I bought
it Nov. 2010). It is a 1976, but the block (and block only,
as far as I can tell) is from a 1980. The emissions, distributor,
carb, etc. all seem to be original 1976.

I don't know why a PO installed the carb cooling fan.
The fan has never run since I've had it. Of course, that might be
because it's not wired correctly...I'll have to check that out.

-Phrog

There is a thermostat which mounts to a bracket on the plate above the manifolds. It connects (I think) to the computer which operates a relay to make the fan come on.