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Shark Bait
05-31-2008, 07:37 PM
Put mine in this afternoon and drove around for several hours. At first take, I think I like it. My 80 definitely idles smoother & quieter and I think it performs better. Seems nicer to drive. Could just be the power of suggestion, but so for it's good. :thumb:

nakman
05-31-2008, 09:21 PM
did mine today too. Also did new spark plugs and changed the oil. Truck seems to run ok, despite the noisy PS pump, but that'll get corrected soon enough.

Felt good to finally get a little wrench time in. :beer:

jjhancock
06-01-2008, 11:30 PM
Is this the LandTank MAFsensor or did I completely miss the boat on a cool new mod for my 80? I'm interested to hear more about it!

corsair23
06-02-2008, 02:04 AM
Is this the LandTank MAFsensor or did I completely miss the boat on a cool new mod for my 80? I'm interested to hear more about it!

Yes it is :D

Wish I had mine installed but they'll have to wait until probably after the Rubicon trip...Chris and Tim, any tips on the install? Matt and I will be installing his on Thursday along with some other tidbits :thumb:

Also, were your housings a little "boogered" up? Nothing major, just superficial shipping "wounds" to the outside of the housings on all 3 I picked, and probably something a black sharpie can probably take care of I think :hill:

Hants
06-02-2008, 08:44 AM
Also, were your housings a little "boogered" up? Nothing major, just superficial shipping "wounds" to the outside of the housings on all 3 I picked, and probably something a black sharpie can probably take care of I think :hill:


Bargain prices, bargain pieces. :rolleyes:

:lmao:

Shark Bait
06-02-2008, 09:31 AM
Chris and Tim, any tips on the install? Matt and I will be installing his on Thursday along with some other tidbits :thumb:
:

Yes. Not having messed with it before, the "locking tab" is the white piece inside the plug. I managed to break the locking tab that keeps the plug locked in the sensor. I don't think it's a major deal. The plug is in there pretty tight. I might try and glue the tab back in. I might not. Any idea how much the replacement plug body is? :o Also, old eyes had a little trouble seeing the pin latches, but I got that figured out. Otherwise it wasn't too bad. :p:

What's the discussion about intake air temps? Do they need to be lowered somehow?

60wag
06-02-2008, 01:07 PM
The wire locking tabs took me a few minutes to figure out. The instructions aren't too detailed. FOrtunately the plastic in the connector is isn't too brittle, (unlike some other cars I own.)

The intake air temp discussion is unrelated to the MAF mod. I just happened to get my test going at the same time as the MAF install. The goal with lowered the air temp is to get the density up - just like adding an intercooler to a turbo or a blower.

jjhancock
06-02-2008, 01:34 PM
Very interested to hear what you guys have to say about the difference in performance and / or any mpg increases. Keep us posted!

corsair23
06-02-2008, 04:43 PM
Yes. Not having messed with it before, the "locking tab" is the white piece inside the plug. I managed to break the locking tab that keeps the plug locked in the sensor. I don't think it's a major deal. The plug is in there pretty tight. I might try and glue the tab back in. I might not. Any idea how much the replacement plug body is? :o Also, old eyes had a little trouble seeing the pin latches, but I got that figured out. Otherwise it wasn't too bad. :p:

What's the discussion about intake air temps? Do they need to be lowered somehow?


I "think" the plug body is pretty cheap IIRC from what I've read (on MUD)...And sorry for confusing the issue re: the MAF mod and IA temp study. Just figured if Bruce was looking for an apples to apples comparison Hants might be the guy on that :thumb:. I'm not sure where the IA temp sensor is and what, if any, effect the freer flowing MAF might have.

Red_Chili
06-03-2008, 09:52 AM
So with you guys going for lowered air intake temps...
The consensus elsewhere (and seems based on experience) is that with colder temps (and more air density), the ECM balances with more fuel, resulting in more power.


And worse economy.

Is that what you are shooting for?

Corbet
06-03-2008, 10:45 AM
I installed mine on Friday. Drove to Durango and back this weekend. I have not topped off the tank yet from the return drive, but I did not see any improved fuel economy after the first two tanks. I remain at 17.4 MPG for HWY driving and actually a little higher goofing off around town?

I'll let you know what the 3rd tank shows.

But:
1. How long does it take the ECU to adjust to a new MAF sensor?
2. Could those of you who have seen an increase in economy have benefited just as much from cleaning your existing MAF sensor?

Over all I "think" the truck runs a little smoother at and just off idle, but as Chris pointed out it could just be a $300 "power of suggestion"

Uncle Ben
06-03-2008, 10:56 AM
I installed mine on Friday. Drove to Durango and back this weekend. I have not topped off the tank yet from the return drive, but I did not see any improved fuel economy after the first two tanks. I remain at 17.4 MPG for HWY driving and actually a little higher goofing off around town?

I'll let you know what the 3rd tank shows.

But:
1. How long does it take the ECU to adjust to a new MAF sensor?
2. Could those of you who have seen an increase in economy have benefited just as much from cleaning your existing MAF sensor?

Over all I "think" the truck runs a little smoother at and just off idle, but as Chris pointed out it could just be a $300 "power of suggestion"

Couple of questions for ye....

Have you removed and plugged your fuel pressure regulator and did you pull the EFI fuse or disconnected the battery for at least 5 minutes after installation so the ECU can relearn?

DaveInDenver
06-03-2008, 11:03 AM
Have you removed and plugged your fuel pressure regulator
Whatcha mean here? Removed and plug the FPR? Do you mean plug the vacuum port, turning it essentially into just a pulse damper? Roger Brown suggests for the 22R-E to reroute the FPR vacuum to come straight off the intake and bypass the VSV circuit, but it's still supposed to adjust for manifold vacuum.

Corbet
06-03-2008, 11:07 AM
Have you removed and plugged your fuel pressure regulator and did you pull the EFI fuse or disconnected the battery for at least 5 minutes after installation so the ECU can relearn?

yes & yes (well not after but during as a standard precaution when working on any part of the electrical system)

Uncle Ben
06-03-2008, 02:52 PM
Whatcha mean here? Removed and plug the FPR? Do you mean plug the vacuum port, turning it essentially into just a pulse damper? Roger Brown suggests for the 22R-E to reroute the FPR vacuum to come straight off the intake and bypass the VSV circuit, but it's still supposed to adjust for manifold vacuum.

Yes. The sensor Rick uses is much more linear in range witch allows the ECU to change the duty cycle of the injectors much smoother and yo a greater degree, Having the fuel pressure change suddenly off idle or under load will create a rich condition.

Corbet
06-06-2008, 02:28 PM
Finally filled up for the 3rd time this morning. 17.1 MPG. So after repeating almost the same 600-700 mile test I got for all practical purposes the same MPG with the new MAF sensor.

What are others getting? Any thoughts to my numbers?

nakman
06-06-2008, 03:52 PM
I'd be very happy with 17.1. My "baseline" numbers are going to and coming back from Moab, where I'm typically in the 13.4 range. I haven't really driven the 80 much (and try not to) since the MAF mod, so my next real test will be going out to Rubithon.

[rubithon hijack]
In fact I'm kind of looking forward to seeing how 10 of our trucks all compare, tank after tank, seeing how the S/C guys do compared to the non-S/C guys, the MAF mods vs. the non-MAF, etc. Maybe we should start a little pool.. whose 80 will get the best and worst MPG? [/hijack]

treerootCO
06-06-2008, 04:00 PM
All depends on driving style. Those that can keep out of it, won't see much of a change. Those who constantly drive WFO are more likely to see a gain. Closed loop operation is increased by the new MAF and, in theory, will maintain closed loop operation throughout a wider range of situations than before.

Hants
06-06-2008, 04:08 PM
I had a "lopey" idle for about a week after I installed mine. My best guess was that it took 6 or so starts & runs to update the LTFT (and whatever other adjustments the ECU "remembers"). It's been rock-steady since.

You should have simply removed the vacuum line to the FPR, NOT plugged it.

I have tracked virtually every tank of gas since I bought my rig. Comparing the 6mo before the MAF and the 6mo after:
Before:After
Best Tank - 15.2:15.5
Average - 11.0:12.9
Median - 12.9:13.4

I tend to experiment in different areas over time (both before and after), but no major changes that would explain the MPG improvements (other than the MAF).

In looking a the actual data since the MAF installation (12.5, 11.8, 14.6, 14.1, 13.5, 13.9, 13.4, 7.0, 13.7, 13.0, 12.8, 11.2, 15.5, 13.5, 12.5), it looks like the first two tanks had a little lower mileage. Could have been me playing with WOT air flows, though, rather than something intrinsic.

Do you notice difference when you're driving down the freeway?

Hants
06-06-2008, 04:12 PM
[rubithon hijack]
In fact I'm kind of looking forward to seeing how 10 of our trucks all compare, tank after tank, seeing how the S/C guys do compared to the non-S/C guys, the MAF mods vs. the non-MAF, etc. Maybe we should start a little pool.. whose 80 will get the best and worst MPG? [/hijack]

Someone mentioned to me that the ECU's in 96 are different than 97. Specifically, driving a 96 and a 97 in tandem (same route, same time, same speed, same trip), the 97 consistently got ~1MPG better than the 96. I'd be curious to see if that pattern holds out on your trip.

And how about those snorkles? Exhaust reworks?

Hants
06-06-2008, 04:13 PM
All depends on driving style. Those that can keep out of it, won't see much of a change. Those who constantly drive WFO are more likely to see a gain. Closed loop operation is increased by the new MAF and, in theory, will maintain closed loop operation throughout a wider range of situations than before.

I think you may have just hit the nail on the head!

Since the MAF, I can no longer get into open loop unless I'm at WOT. Even just a smidge off of WOT under heavy load at altitude, it stays closed loop. The only other condition where I can force open loop is shifting into 2nd and holding high RPM at very heavy loads.

corsair23
06-06-2008, 04:21 PM
You should have simply removed the vacuum line to the FPR, NOT plugged it.

The instructions say to pull of the vacuum line and plug/cap the ends that the line use to be attached to :confused:. Rick even includes the little caps, although they are way too long and need to be carefully and expertly trimmed down to fit...Just ask Matt :)

Corbet
06-06-2008, 04:24 PM
I'd be very happy with 17.1. My "baseline" numbers are going to and coming back from Moab, where I'm typically in the 13.4 range.

I'm still stock height and tires. With a 4" & 35" I'm sure my 17+ would decrease.

Those that can keep out of it, won't see much of a change.

This probably explains most of it, however I'm constantly running wide open to get over the passes.


You should have simply removed the vacuum line to the FPR, NOT plugged it.

Do you notice difference when you're driving down the freeway?

I plugged them per instructions, you say no?

I have not really noticed real difference with how it drives freeway or city. I'd only say it "seems" a little more sluggish on the pass honesty.

Maybe I'll plug in my scanner on the way home to monitor some things.

Hulk
06-06-2008, 04:33 PM
Mr. Corsair23 and I did my MAF mod yesterday evening. Not hard at all. The truck immediately ran better, just based on my own experience driving the truck every day. No hesitation off the line, smoother operation and shifting. Also, seems like it gained some power too.

I'm running 35-inch tires with 4.88 gears. No supercharger. It's a 1996. I stopped tracking mileage a few months ago, since my speedo is significantly off. I'll use the GPS to track mileage out to the Rubithon and get some numbers.

Honestly, I don't care about gas mileage in my 80 as much as I want more power. All the weight I've added to the truck has made it a beast. If I could find a supercharger, I'd probably buy it.

All in all, I think the MAF mod was worth every penny.

Hants
06-06-2008, 05:07 PM
The instructions say to pull of the vacuum line and plug/cap the ends that the line use to be attached to :confused:. Rick even includes the little caps, although they are way too long and need to be carefully and expertly trimmed down to fit...Just ask Matt :)

My bad. Just checked -- mine IS capped.

There was a big discussion a while ago on MUD, and someone tried to deny LT's empirical results. I just mis-remembered which was which.

Rzeppa
06-07-2008, 01:26 PM
I stopped tracking mileage a few months ago, since my speedo is significantly off. I'll use the GPS to track mileage out to the Rubithon and get some numbers.

I recalibrate mine every year driving to Moab. When I pass milemarker 100 on I-70 I write down the odometer reading. Then when I cross the Utah State line I write down the odometer reading. The difference between odometer readings from 100 miles becomes my new correction factor. Using so many miles gives very good precision. But then, I don't have a GPS

:-)

nakman
06-09-2008, 09:37 PM
Overall, I'm fairly happy with the MAF mod. I'm not quite as blown away as, say, Nay (http://forum.ih8mud.com/3374857-post68.html) is, but still this seems to make the truck run a little better. This morning going north on 470 between Morrison Road and I-70 I was able to hold that hill past Bandemiere, 70 mph without it shifting out of overdrive. Before to do this I would have had to have been in power mode, or turned O/D off. So I guess it's got a little more "stayin power..."

Looking forward to seeing some highway mileage next week.

Nay
06-10-2008, 08:45 PM
I dig it. But...I run 5.29's and 35's, and NVH is way down at upper RPM, and it is shifting smoother at higher RPM's. It doesn't change the world, it's just enough with my *light* 80 that I'm in the left hand lane passing up Monument Hill vs. the right hand lane bogging. The rig feels right now, not supercharged or anything, but just more ready to pull, without the NVH, rather than always on that edge of bogging down, even with the low gears. That's a subtle change, but one for me that increases driving pleasure and makes me more willing to hit 3,500-3,700 RPM for brief stretches at 70 mph in 3rd vs. slowing down to that higher pass crawl.

IMO, very well spent $300...but...my 80 is a bit atypical (gear ratio/tire size, weight) so my experience may be outside the statistical norm. I do carry my whole family of six on long trips, and I'm pretty sensitive to NVH issues despite my tire choices :hill:, so this is a mod that hits home for me in the dual use arena.

Hulk
06-11-2008, 01:43 AM
I have no idea what NVH is.

DaveInDenver
06-11-2008, 06:50 AM
NVH usually means Noise, Vibration, Harshness.

Hants
06-11-2008, 09:01 AM
Nevada Highway -- you're on one about now, aren't you?




:beer:

Hulk
06-11-2008, 11:57 AM
Nope -- leave next Monday. 5 days and counting. :D

Crash
06-11-2008, 12:15 PM
Drove to Leadville for dinner yesterday and got a good chance to work out the MAF modded 80 into major headwinds all the way up there. SOTP impressions are that power has been enhanced, the transmission is now smarter and thinks more like me, i.e. it downshifts when I think it should and manual downshifts aren't required nearly as often. This was with the power button NOT engaged. At the elevations west of Georgetown, the engine was beathing much more easily and revved more freely with less skinny pedal required to accelerate or maintain desired speeds. As the headwind was major, I didn't fret about mileage so power was what was tested and the Landtank MAF mod gets two thumbs up from me in that regard. Mileage will be the test target in a couple of weeks when I head to Kansas City and it will be reported upon at that time. However, even with the headwinds and large doses of skinny pedal, we drove 198 miles on half a tank of gas. The winds had died down by the time we returned to Denver so didn't have the tailwinds on the way home.

Nay
06-12-2008, 07:56 PM
NVH usually means Noise, Vibration, Harshness.

Yea, sorry, noise, vibration, harshness. My stereo is much louder now, conversations with :Princess: a bit quieter :D

Hants
06-24-2008, 12:19 PM
Another update:

I live at about 7300ft. Just returned on a trip from Colorado Springs to Pagosa Springs, about 280 miles each way, and the resort is at about 7500ft. Between, lowest elevation is about 4700, and you go through a couple of passes at about 10000 (10,800 & 9,400).

15.4MPG going there -- best ever
17.2MPG returning -- unbelievable!

The only time I can get into Open Loop is at or above 3,550 RPM and significant engine load, or at WOT.

Held moderate grades very well without downshifting. Had power to pass (slowly) when I needed to.

Engine/tranny shifted very well. Sometimes I felt that it didn't downshift soon enough, but by watching the scangauge, it was doing VERY well at maintaining better mileage. In a couple of borderline zones, I forced a downshift and had an immediate drop in mileage (sometimes >5MPG difference).

There were a couple of spots where it was obvious that the cruise control was going to do its "cut out" game. In those spots, I put my foot back on the peddle, and manually turned it off -- waste of gas to try to re-gain speed on steep grades.

On the way back, I didn't force 60MPH in 2nd on the passes -- kept it under 3550RPM to stay in Closed Loop (about 1/2 throttle!). Historically, I'd keep at 60-62 on the steep grades in second (about 4200 RPM).

I think I only passed twice on the return, probably 6 on the way there. Passing was: time the oncoming traffic, WOT about 1 second before the oncoming car cleared me, hold it until passed+100ft, back on cruise control. Didn't really worry about grades (none were on steep down or up grades). Speed post-pass was generally 80+.

Had the cruise control set at 65 both ways. Stopped for lunch in Walsenburg both ways, and stopped at the Brewery in Alamosa (owner is a Cruiser dude -- don't recall his name) to fill up my growler both ways. Both trips started in the morning and ended in the late afternoon.

Setting the Cruise at 65 versus 75 makes a material difference in mileage, and doesn't add much time to the trip. Keeping the RPM under 3550 (staying in Closed Loop) adds another real kicker to the mileage.

Does anyone still have the stock MAF & 33's? I don't recall tracking which conditions caused open loop with the stocker; I just remember seeing it in Open much more.

corsair23
06-25-2008, 01:35 AM
Does anyone still have the stock MAF & 33's? I don't recall tracking which conditions caused open loop with the stocker; I just remember seeing it in Open much more.

Snif...snif...yep :hill:

Want me to check on something before I get around to the upgrades? Of the new MAF and housing that is.

Hants
06-25-2008, 11:13 AM
I'd be curious to know the following:

1. Set your SG to monitor LOD, RPM, OPEN/CLOSED, TPS
2. Monitor OPEN/CLOSED LOOP as you're driving
3. At what RPM/LOAD/TPS combinations does it switch to OPEN loop?
4. When do you hit those combinations?

I used to hit Open Loop merging onto the freeway and going up even moderate grades. Now, I only hit Open Loop going up steep grades at high altitude (and then, only when I force 2nd and keep the RPM too high).

Hulk
06-25-2008, 12:15 PM
Jeff, I still have your Scan Gauge II. I'll bring it to the RS meeting next week, unless you want it earlier.

Red_Chili
06-25-2008, 12:56 PM
Man, I gotta get me one of them SGs.
Right after all the other things I gotta get. Like a second job. :(
:lmao:

Hants
06-25-2008, 01:29 PM
Man, I gotta get me one of them SGs.
Right after all the other things I gotta get. Like a second job. :(
:lmao:

At current (and future!) gas prices, it could pay for itself in a few tanks, if you can use it to increase your MPG. :thumb:

Being able to monitor my instantaneous and "today" MPG is really useful. I use it to test various driving "habits". It allows testing over short periods of time, and getting immediate feedback. No need to wait for a fillup (and thereby accumulating confounding data).

It also allows before & after monitoring as you make mods (like LT's MAF).

Red_Chili
06-25-2008, 01:56 PM
I have so many things that could pay for themselves, I should be living on the residuals and put the difference in my IRA... :lmao:

I do know that keeping my throttle at 1/8, coasting wherever possible, and keeping my speed down has certainly paid for itself. Helped with that accepting, inner peace thing too.

Hants
06-25-2008, 02:16 PM
I have so many things that could pay for themselves, I should be living on the residuals and put the difference in my IRA... :lmao:

I do know that keeping my throttle at 1/8, coasting wherever possible, and keeping my speed down has certainly paid for itself. Helped with that accepting, inner peace thing too.

Keeping an 80 at 1/8 throttle would just burn gas -- you'd be going basically nowhere! :hill:

Red_Chili
06-25-2008, 02:47 PM
The joys of 3.4 litres and 5.29s on 35s... towing, now that requires a bit more throttle.

corsair23
06-25-2008, 05:54 PM
Jeff, I still have your Scan Gauge II. I'll bring it to the RS meeting next week, unless you want it earlier.

I'll probably swing by and grab it and the net one night this week. I'm going through SG withdrawls :hill:. Plus, we are heading to Grand Lake Saturday morning so it would be nice to have it for the trip and get Hants his data :thumb:

Nay
06-26-2008, 08:44 PM
Well, I just spent a few days in Keystone with a side trip to Vail, what a great difference up towards Eisenhower, I was often passing instead of puttering in the right hand lane, was always able to easily cruise at the speed limit. Coming up west Vail Pass is still slow, and west to Eisenhower is still slow, but much better.

Fuel economy? Well, I averaged it out over 2 tanks and got 14 mpg on 1/3 city 2/3 highway. This with family of six onboard with gear. 5.29's and 35" Intercos.

I don't think my fuel economy is much improved since I've been getting these results with 5.29's anyway, but no question how much better it is breathing on the high passes. My wife even noticed as a passenger.

I'd say for the high passes that the MAF mod has done as much as the 5.29's, or perhaps best to say they complement each other very well.

It doesn't need to pay for itself. I'll spring :D

Hants
06-26-2008, 09:39 PM
Based on my recent testing, you'll probably see a boost in MPG by keeping the RPM below 3550 on the passes.

:beer:

Nay
06-26-2008, 10:21 PM
Based on my recent testing, you'll probably see a boost in MPG by keeping the RPM below 3550 on the passes.

:beer:

Yep, it's feeling pretty ideal for what this rig is. I don't hit those kind of RPM's up the passes because my gearing in 3rd is lower and in 2nd is quite a bit higher, but I'm easily in stock range for fuel economy on a hardly stock rig. No way I'm touching 17 mpg, but 15 highway when I keep it at 65-68 mpg is right on.

Problem is all this good stuff keeps tempting me to go 37's :D

corsair23
07-11-2008, 12:45 AM
I'd be curious to know the following:

1. Set your SG to monitor LOD, RPM, OPEN/CLOSED, TPS
2. Monitor OPEN/CLOSED LOOP as you're driving
3. At what RPM/LOAD/TPS combinations does it switch to OPEN loop?
4. When do you hit those combinations?

I used to hit Open Loop merging onto the freeway and going up even moderate grades. Now, I only hit Open Loop going up steep grades at high altitude (and then, only when I force 2nd and keep the RPM too high).


Hants, I have some data for you :thumb:

I set my Scangauge II up as requested above and noted the following during a recent trip to Grand Lake (up and back and then up and back again :))

Some baseline numbers first:

Idle at a stop light, AC off: LOD = 19 to 21 | TPS = 8 | RPM 610 to 625
Idle at a stop light, AC on: LOD = 25 | TPS = 8 | RPM 700ish
Off throttle (coasting) to a stoplight, AC off: LOD drops to 10 then gradually climbs back up to ~20 when stopped.

Now, here are some readings when my rig went into OPEN loop:

LOD - RPM - TPS
58 - 2500 - 38
61 - 4300 - 66
63 - 3400 - 58
60 - 4200 - 60

Some general observations on when the rig would go into OPEN loop:

Anytime you lift off the throttle and coast
Pretty much anytime RPMs > 3750 (maybe even a little lower)
Pretty much anytime the TPS > 60
Obviously when TPS > 60 and RPMs > 3750 the LX would most certainly be in OPEN loop. It appears max TPS (for me at least) is 75 based on testing which would be WOT. So at 60 TPS that is 80% WOT.

As for when the above scenarios fit. The first one (58/2500/38) was pulling away from a stop light in town, going up a slight hill, before the trips. The other occurrences were all while going up Berthoud pass mainly although anytime I hit TPS > 60 and/or RPMs > 3750 the LX would be in OPEN loop which was pretty much anytime I was trying to climb a hill :)

It will be interesting to try this test again after I install the MAF housing and new MAF and see what changes.

nakman
07-11-2008, 09:26 AM
I realize now that I'll probably never see the big benefit to this mod. I never exceed 4000 rpm's, and rarely go above 3500, would only do that going up I-70 towards the tunnel or something. So I probably never get into open loop?

I've always had this theory that the my big ol' 1FZ-Fe will last longer if I didn't push it so hard, and 5 minutes more drive time is nothing plus I'll use less gas and oil.. but maybe I'm just a pansy. :confused:

Hants
07-11-2008, 10:02 AM
Great data, Jeff!

My Idle load is 13-15 (from memory). The lowest I've seen is 3, when coasting down a steep hill.

The OPEN on no throttle is related to the fuel cutoff. Mine isn't 100% consistent (most times goes to OPEN when I let off the throttle at highway speeds, but not always, sometimes goes to OPEN when I let off the throttle in the city).

My mas TPS is 76, IIRC. There's a separate switch for WOT. On my rig, it triggers just before I hit the floor.

I think there's a correlation between LOD and RPM to go into OPEN loop. On mine, if load is >60 (maybe a bit more), I go into OPEN as soon as my RPM goes over 3550. If load is <60, I have been able to get as high as 3900 RPM in CLOSED loop (maybe even higher -- I haven't really pressed this limit).

The only time I see OPEN loop these days is going over passes. And that's controllable by shifting into 2nd and driving at 50MPH (instead of the 60 to 65 I used to push). On my rig, 50 is right at 3500 RPM. This sometimes means running 1/2 throttle in 2nd (not enough power to hold 3rd).

We just returned from a trip to Breckenridge. We normally travel the back roads (Hoosier pass down to the 24 to Colorado Springs. In this case we took a "slight" detour to Crested Butte over Cottonwood pass. Drove from Breck down to Buena Vista, across Cottonwood Pass, over county roads (mostly unpaved) to just South of Crested Butte, then into Crested Butte and drove around some neighborhoods up by the lifts, then retraced our route across Cottonwood pass, and back home. Had a large pod (hangs off the back, and covers most of the sunroof, width is just narrower than the rails) on the roof, and a full load. I got 15 MPG on the whole trip. I'm amazed at the MPG I get now that I'm more careful with the throttle.

I'm surprised by that first OPEN transition on yours. I haven't seen anything like that since I've been monitoring.

I suspect that you'll see lower LOD values across the board once you install the MAF. I don't recall if the SG actually reads the MAF on our rigs. I have a different ODBII reader that does. The max MAF I could get stock was just under 17 lbs/min of air. With the new MAF goes over 19.

I'll be curious if your LOD>60+RPM>3750==>OPEN pattern continues. I wonder why the difference?

Hants
07-11-2008, 10:14 AM
I realize now that I'll probably never see the big benefit to this mod. I never exceed 4000 rpm's, and rarely go above 3500, would only do that going up I-70 towards the tunnel or something. So I probably never get into open loop?

We don't have a enough data on various rigs yet to really have this OPEN/CLOSED thing characterized yet. If we can get more locals to post up their info, we'll get a better idea of patterns.

I'll bet you see noticeable differences. If nothing else, the little extra oomph is a blessing.

I've only seen one post here or on MUD of NO increase in MPG, and, IIRC, that was only on one particular route.

Do you have a SG? If so, monitor when/how often you're in open loop (at a minimum), before and after the MAF.

Nay
07-11-2008, 10:45 AM
I realize now that I'll probably never see the big benefit to this mod. I never exceed 4000 rpm's, and rarely go above 3500, would only do that going up I-70 towards the tunnel or something. So I probably never get into open loop?

I've always had this theory that the my big ol' 1FZ-Fe will last longer if I didn't push it so hard, and 5 minutes more drive time is nothing plus I'll use less gas and oil.. but maybe I'm just a pansy. :confused:

I never saw, and haven't realized, mpg as the benefit. Engine smoothness under better power delivery at higher RPM has been the clear benefit for me, and it sounds like I drive more like you do (I cruise at 65-70).

This mod may allow more driver behavior flexibility, and therefore mpg increase via throttle management, but without changing any variable but the MAF/sensor I haven't seen any increase in fuel economy. I can actually pass up high on I-70 now, where before I was always in the slow lane, and my engine isn't really loud during the process.

I think the mpg benefit is emerging in a $4/gallon world were justifying the cost to :Princess: works when you can calculate a short term breakeven. I just don't think it's the MAF that's getting you there as much as it's driving style, outside of saying that more power can enable less of the skinny pedal.

Much like my 5.29's. I have picked up 1-2 mpg increase, but only if I keep speed down under 70. If I still want to drive 75, I still get 12 mpg. But I have good power delivery at 65 because I'm up in the power band with higher RPM, so if I'll cruise at 65-68 I get the better economy. Same would have been true I am sure with the stock gears, except RPM was so low it was bogging all the time at our altitude (notice the posts on MUD above improving mpg by going up to 285's at sea level).

So the big benefit on the label isn't mpg, but it may be an achievable output with a modification of driving style. You and I may have simply already had that modified driving style, so a bit mo' powa and NVH reduction are the only real benefits to this mod (I think those are bigger on a pig on 35's anyway).

corsair23
07-11-2008, 01:32 PM
I realize now that I'll probably never see the big benefit to this mod. I never exceed 4000 rpm's, and rarely go above 3500, would only do that going up I-70 towards the tunnel or something. So I probably never get into open loop?

I've always had this theory that the my big ol' 1FZ-Fe will last longer if I didn't push it so hard, and 5 minutes more drive time is nothing plus I'll use less gas and oil.. but maybe I'm just a pansy. :confused:


Tim,

You would probably be surprised, as I was, at how often your rig goes into OPEN loop. It would have been easier to collect the data had I had a computer with software that would record the data for later analysis. As it was a challenged to try to monitor the SG for the exact moment the LX would go into OPEN loop while driving so instead I just started to watch for consistent parameters. I would say more often than not once the RPMs hit 3500 the LX would go into OPEN loop but it is hard to catch because the values change so quickly. Watching the LOD and TPS values is easier because they don't change as fast.

I'm seriously considering 4.88 gears despite only running 285s just to get the rig to run in a more efficient power band. Often just to get the LX moving on some of the switch backs on Berthoud pass after a tight 20 mph corner the tranny would shift down into first. Instant OPEN loop at that moment and the second the LX would upshift into 2nd it would start to bog down. If I could keep the speed up and the LX in the 3500 RPM range then I could generally keep her in CLOSED loop going up the hill. I wasn't trying to set any speed records, just stay close to the speed limit :)

Now that I have some baseline data for my rig I should be able to see what, if any, changes the MAF mod will have on my rig. I'm holding off until I get the tune up done so as to not have any of those effects blurring the advantages (if any) of the MAF mod.

Hants
07-11-2008, 02:30 PM
Now that I have some baseline data for my rig I should be able to see what, if any, changes the MAF mod will have on my rig. I'm holding off until I get the tune up done so as to not have any of those effects blurring the advantages (if any) of the MAF mod.

Speaking of tune-ups: If your O2 sensors are > 100K, you should consider refreshing them along with your normal tune-up stuff (plugs, wires, cap & rotor, air filter). And check to make sure your exhaust isn't too crunched (particularly where it goes under the frame rail, and at the end after the resonator).

corsair23
07-11-2008, 03:00 PM
Speaking of tune-ups: If your O2 sensors are > 100K, you should consider refreshing them along with your normal tune-up stuff (plugs, wires, cap & rotor, air filter). And check to make sure your exhaust isn't too crunched (particularly where it goes under the frame rail, and at the end after the resonator).

Hmmm...The LX has ~108K miles on it and I'm sure the O2 sensors are the originals. I considered replacing them but the comments I had read were to leave them be until they start throwing a code :confused:. Maybe I should consider going ahead and doing them anyway?

As for my exhaust...It is fine except the end which is squished, yet again, due to CM :D. But, I seem to be getting slightly better gas mileage since CM08 so I was thinking the extra exhaust restriction was helping :hill:

Hants
07-11-2008, 04:56 PM
There are several threads on MUD regarding the O2 sensors and their (perported?) affect on performance. My experience with pre-hard-failure-replacement was positive (mileage up a bit, power up a bit, sleep quality much improved).

I finally gave up on my exhaust tip and took a sawzall to it. :hill:

corsair23
07-11-2008, 05:25 PM
There are several threads on MUD regarding the O2 sensors and their (perported?) affect on performance. My experience with pre-hard-failure-replacement was positive (mileage up a bit, power up a bit, sleep quality much improved).

I finally gave up on my exhaust tip and took a sawzall to it. :hill:


Good info on the O2 sensors...I'll have to look into them then.

As for the exhaust tip...We discussed the sawzall mod after CM07 but I still have not done it - the squished tip is like a badge of honor for me :) :lmao:

Hulk
07-11-2008, 05:34 PM
Sawed my exhaust tip off after Henley goaded me into it. My MPG subsequently increased by 0.00185%.

treerootCO
09-03-2008, 11:46 AM
I put my new MAF sensor in last weekend and didn't notice the rough idle that some have reported. The engine was cold but I had the ECU unplugged for a few hours so that may have helped. It made me feel good that a mod was bringing my '95 up to date with a newer technology and that alone was worth it to me. Unlike the snake oil remedies for better economy and performance, this was an actual update. First impression is that the engine appears to be smoother at higher RPMs. The usual tune up items like plugs, wires, etc. are all original to the truck and have been under the bonnet for 178,000 miles. Those will be next...