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Stumble/Lean at WOT between 2600-3k RPM


thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239293 posted 08/30/17 05:10 PM     Remind Me!  Send Private Message   Edit Post      
I have a new issue with 1025. About 2 months ago I popped a coupler @ the GM-MAF. Ever since I have had a stumble/lean issue between 2600-3000rpm. I have changed out the MAF with no changes in what is going on. I am at WOT and it does it. Only seems to be under load. If I knew how to upload a log I would.

Mods are in my signature.



Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (2601:803:c402:8c) | Report this post to a Moderator

GSTwithPSI
A hole
820/1000
1837/2000



Galant VR-4 org Post #: 1239299 posted 08/30/17 09:47 PM     Remind Me!  Send Private Message   Edit Post      
I'd really only be able to help with a log.

You can upload it to any hosting site (dropbox, google, OneDrive, etc) and post a link to the file here.

I'm not a huge fan of the GM MAFs, honestly. They are notorious for being finicky.



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thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239305 posted 08/31/17 07:51 AM     Remind Me!  Send Private Message   Edit Post      
here is the log on Google+ log



Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (2601:803:c402:8c) | Report this post to a Moderator

transparentdsm
I have to say something dumb Member
138/2000


Galant VR-4 org Post #: 1239329 posted 09/01/17 07:21 AM     Remind Me!  Send Private Message   Edit Post      
from 2400 - 3500 you have a weird variation from your LC2 to your A/F estimate. those two need to line up better. look like not enough fuel.



138/2000 - BG - Dorothy

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transparentdsm
I have to say something dumb Member
138/2000


Galant VR-4 org Post #: 1239330 posted 09/01/17 07:46 AM     Remind Me!  Send Private Message   Edit Post      
try bringing your hz in the 250 section up to 12.8. for some reason you have it at 11.7 in that area and it causes for an unsmooth flow. ive never tuned a maf on DSMlink as i went striaght to SD, but this is the only thing i see off. Brett is a bit smarter and should know more about this...



138/2000 - BG - Dorothy

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GSTwithPSI
A hole
820/1000
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Galant VR-4 org Post #: 1239345 posted 09/01/17 07:48 PM     Remind Me!  Send Private Message   Edit Post      
Thom, which log am I supposed to be looking at? There's like 5 in your drive.

I'll go through the settings tab, and point out the things I'd fix. LMK which log shows the symptoms you're talking about, and I can give you some feedback based on that specific log.

Also, it would be helpful if you could fill out this template and paste the information here in this thread. I need this info in order to check fuel settings, and a slew of other parameters: click

1) Adjust your TPS. @ 15 offset on a 101% scale, you TPS is way out of whack: click

2) MAFcomp table needs work. Those peaks you have in your MAFcomp table should be rounded off to make a nice smooth curve. That spike at 1,500hz is definitely fucking things up. If you have to adjust large peaks in, you probably have an underlying issue with the car. You have to remember, large changes in the values from cell to cell will throw off the WBfactor. Depending on what I'm seeing in my logs, I will generally take the WBfactor and cut it in half, and then adjust the MAFcomp slider. Afterwards, I'll do another pull or 2 and see where that leaves me. If you make large changes all at one time, it's going to be hard to see how the car actually responds during say, a 3rd gear pull.

Your MAFcomp table looks like most I've seen from people using a GM MAF. For the most part, they are more of an ass pain than they are worth. I've never seen one tuned consistently across the board that worked great all around (cruise, idle and WOT). In contrast, I've tuned multiple cars on Evo MAFs that ran like stock.

If you could, point me to a log where you've collected good data and want feedback on how to dial in the MAFcomp.

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thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239346 posted 09/01/17 09:33 PM     Remind Me!  Send Private Message   Edit Post      
Thank you Shane and Brett. I made the changes Shane mentioned. Brett, I truly apologize for all the logs in there. That folder was supposed to only have one in it. I will remove the others and leave two. Once will be called oldlog (the one where you saw some of the crazy settings. The other (new log) is after making the TPS changes and doing a WOT pull in 2nd and 3rd (to around 5300 - 5900rpm in each gear). I believe there may be a MAF Comp adjustment there too. It still has that 1500 spike in there.

I will also look at adjusting the TPS.

I am very tempted to ditch the MAF for either SD or an EVO MAF (if I go with the EVO MAF, I will have to work something out with a friend and see if I can get his TIAL the recirculates in trade for my VTA Tial (Since I assume I will need to recirculate with an EVO MAF). The only thing about the SD move is getting a TB elbow that has the bung setup as there really isn't anywhere here that does it (and I haven't seen one for sale in a while.)

Template is below:

1). Any boost, vac, or exhaust leaks?
No
Boost leak tested 5psi above your max boost with no leaks?
Yes (30 PSI test

2). Verified mechanical timing?
Yes

3). Verified base timing?
Yes

4). Ignition system
COP or Stock Coil: Stock
Wire brand and Age: NGK/1 year
Spark Plug brand, type and Gap: NGK-BPR7ES/.026

5). Motor health (Compression Test)
Cylinder 1: 158
Cylinder 2: 158
Cylinder 3: 159
Cylinder 4: 157

6). Performed basic throttle body adjustments?
Idle Switch: Yes
Throttle Cable: Yes
TPS: Yes
BISS: Yes

7). Compression ratio
8.3:1

8). Any known bad sensors or brittle wiring?
No

9). Any DTC/CEL codes?
No

10). Electrical system
Car off (not running): 12.4 volts
Car running: 13.9 volts

11). Base fuel pressure and injector values
Base Fuel Pressure: 43
Injector Size (cc/min): 1200

12). Properly calibrated and configured wideband sensor
Sensor Brand: LC2
Calibration Date: APR 2017

13). Type of fuel
Type: 93 Octane
Percent of Ethanol: 8%

14). Watched ECMlink how-to videos?
Yes



Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)


Edited by thomcasey (09/01/17 09:40 PM)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (2601:803:c402:8c) | Report this post to a Moderator

transparentdsm
I have to say something dumb Member
138/2000


Galant VR-4 org Post #: 1239349 posted 09/02/17 08:53 AM     Remind Me!  Send Private Message   Edit Post      
so i looked at your new log and i think your MAFcomp should look a little more like this.please dont use this as i have no idea if its right, but i did what i though was needed to get the A/F estimate and actuals to line up. looking at your MAFcomp it goes up and down all the way to 1500 Hz then drops down at 1600 hz and as you watch it go low it pulls the actual A/F away from the estimate dramatically.





138/2000 - BG - Dorothy

Posts: 3402 | From: Klamath Falls, Or | Member Since: 07/27/11 | IP: (71.89.204.234) | Report this post to a Moderator

GSTwithPSI
A hole
820/1000
1837/2000



Galant VR-4 org Post #: 1239353 posted 09/02/17 10:35 AM     Remind Me!  Send Private Message   Edit Post      
That second gear pull doesn't give me enough good data to work with. I could make adjustments based on that pull, but I'm positive they would be off. I need a 3rd gear pull from around 2,500rpm to whatever redline for your car is. Based on that, I will be able to make accurate adjustments to the MAFcomp table assuming everything mechanical is sound.

Your DA AFR table is set way too rich. On 93 octane, I shoot for 11.0:1 as a baseline for my pump gas tunes. I'd consider leaning out your table. I have a decent baseline table here: click . You can download that and load it into ECMlink if you want.

Your TPS is still jacked up in the "newlog" file. The best way to ensure your TPS is set correctly is to uncheck the "Enable TPS adjustments" box and not allow ECMlink to correct it for you. I've seen dicked up TPS sensors cause a bunch of strange issues, so I never recommend relying on ECMlink to correct for a incorrectly adjusted TPS.

Going SD or an Evo MAF really just depend on your goals for the car. If this is a build that will stay relatively tame, and you plan to drive it a lot, I'd say swap to the Evo MAF. If more mods and power are planned as future goals, I think SD would be the better choice. Both are exponentially easier to tune, and more reliable than the GM MAFs, IMO. I know people who claim they are great, but like I said, I've literally never seen or tuned are car where it performed well all around.



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thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239387 posted 09/05/17 06:19 AM     Remind Me!  Send Private Message   Edit Post      
Thanks Shane,

I have smoothed out the MAFComp. Hopefully i can get a pull in this week.

Quoting transparentdsm:

so i looked at your new log and i think your MAFcomp should look a little more like this.please dont use this as i have no idea if its right, but i did what i though was needed to get the A/F estimate and actuals to line up. looking at your MAFcomp it goes up and down all the way to 1500 Hz then drops down at 1600 hz and as you watch it go low it pulls the actual A/F away from the estimate dramatically.








Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (12.109.79.254) | Report this post to a Moderator

thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239388 posted 09/05/17 06:47 AM     Remind Me!  Send Private Message   Edit Post      
Thanks a bunch, Brett.

I have applied the baseline table. I have also disabled the TPS adjustment and set the TPS properly. (Zero'd .63v closed, 5v WOT). It actually used to be set like that but the bolts securing it may have been a bit loose, allowing it to shift.)

It is difficult to get a location here where I can go WOT from 2500 to 7500 in 3rd gear as the interstate is real busy (especially with troopers), but I will seek out a place.

My goals are to continue to use this as a daily (I ride share with the Wife, so this gets daily treatment when we have to drive separate for an appt.). I have a few feelers out for a 399 MAF and connector/cable. Maybe the Ft. Wayne guys will have one for me. IF not, then I will be getting what I need for SD.

Quoting GSTwithPSI:

That second gear pull doesn't give me enough good data to work with. I could make adjustments based on that pull, but I'm positive they would be off. I need a 3rd gear pull from around 2,500rpm to whatever redline for your car is. Based on that, I will be able to make accurate adjustments to the MAFcomp table assuming everything mechanical is sound.

Your DA AFR table is set way too rich. On 93 octane, I shoot for 11.0:1 as a baseline for my pump gas tunes. I'd consider leaning out your table. I have a decent baseline table here: click . You can download that and load it into ECMlink if you want.

Your TPS is still jacked up in the "newlog" file. The best way to ensure your TPS is set correctly is to uncheck the "Enable TPS adjustments" box and not allow ECMlink to correct it for you. I've seen dicked up TPS sensors cause a bunch of strange issues, so I never recommend relying on ECMlink to correct for a incorrectly adjusted TPS.

Going SD or an Evo MAF really just depend on your goals for the car. If this is a build that will stay relatively tame, and you plan to drive it a lot, I'd say swap to the Evo MAF. If more mods and power are planned as future goals, I think SD would be the better choice. Both are exponentially easier to tune, and more reliable than the GM MAFs, IMO. I know people who claim they are great, but like I said, I've literally never seen or tuned are car where it performed well all around.





Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)


Edited by thomcasey (09/05/17 06:29 PM)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (12.109.79.254) | Report this post to a Moderator

thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239402 posted 09/05/17 06:31 PM     Remind Me!  Send Private Message   Edit Post      
The correction of my TPS, MAFComp have rid my car of the stumble/lean issue. Runs better too. I just ordered a 399 MAF and hard intake. I will probably my end JP switching to that before I get a chance for a pull.



Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (2601:803:c402:8c) | Report this post to a Moderator

thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239741 posted 09/28/17 04:48 PM     Remind Me!  Send Private Message   Edit Post      
Well, installed my new (to me) EVO 8 FMIC, new piping, recirculating Tial and EVO 8 MAF. BLT to 30 PSI, no leaks. I reset the MAF comp to zero and set Link to EVO 8 MAF. Starts like it has two cylinders out and the LC2 regularly goes into open loop. Runs like ass, so much so that a log is near impossible.

GM MAF is back in temporarily.

Are there some settings I am missing? Should I have left the GM-MAF settings for MAFComp in there?



Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (68.45.230.24) | Report this post to a Moderator

transparentdsm
I have to say something dumb Member
138/2000


Galant VR-4 org Post #: 1239811 posted 10/03/17 03:09 PM     Remind Me!  Send Private Message   Edit Post      
when you changed the maf settings did it maybe somehow change injector size and you didn't notice?? ive had weird things happen in link before when the laptop is left plugged in and open. we were tuning my buddies car and we had adjusted the SD table on his car and somehow during the log or playing with things we changed 1 individual injector pulse to a crazy number and the car would run as your explaining yourdoes. we were also on something like 1200 or 1300 cc injectors. and when you put the GM maf back in and loaded the old log the changed setting wasn't there any longer.just a theory.



138/2000 - BG - Dorothy

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thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239812 posted 10/03/17 04:21 PM     Remind Me!  Send Private Message   Edit Post      
Unfortunately, I never changed the injector settings (Mine are 1200cc PTE). When I put the GM MAF back in, I manually set the MAFComp back to what it was before, I didn't reload the old log (that would have been easier though). I do notice the stumble and lean issue is intermittent. I am attaching an image of where it happens. I noticed the WB factor rises when it happens. Now this was during the drive home from work, so some getting on it a little, stop-n-go, traffic.

Logs




Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (68.45.230.24) | Report this post to a Moderator

GSTwithPSI
A hole
820/1000
1837/2000



Galant VR-4 org Post #: 1239826 posted 10/04/17 01:54 PM     Remind Me!  Send Private Message   Edit Post      
A wiring issue, perhaps. How do you have the Evo MAF wired in?

The MAF Comp table should be zeroed out. You'll need to completely recalibrate the table on the Evo MAF from scratch.



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thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239828 posted 10/04/17 02:31 PM     Remind Me!  Send Private Message   Edit Post      
Yea, I zeroed it out. When starting it initially it would barely idle. I lef the MAFComp adjust do its thing for idle, and it set the active MAF compensation setting like this image.



Here are the LOGS . Log that ends with 01 is my attempt to smooth the table, the one that ends in 02 is with the table set by link.

It would idle and start fine with this setting, but ran horrible below 3500rpm. Would stay in open loop. When performing a cruise adjustment, it would cruise fine but idled real lean then stopped idling. Then on restart it sounded like a subie that is missing a cylinder.

It was wired in with a 1g/gvr4 to EVO cable from David/Iceman. I am sure I could be setting the MAF up all wrong, but I can't find much info. I am recirculating the BOV, no boost leaks (tested to 30+ psi)



Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (12.109.79.254) | Report this post to a Moderator

tommyp
Junior Member
1410/2000


Galant VR-4 org Post #: 1239837 posted 10/05/17 01:57 PM     Remind Me!  Send Private Message   Edit Post      
It's a longshot... did you check for a puddle of oil in your sparkplug well? Had the same problem once.

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iceman69510
Turn Right Racing
855/2000
828/1000


Galant VR-4 org Post #: 1239838 posted 10/05/17 02:21 PM     Remind Me!  Send Private Message   Edit Post      
One thought- on a GVR4 there are two green with red stripe wires in the MAF harness (I think I remember that color combo correctly). I know you had to wire on a new harness side plug. Did you get these two sorted and wired correctly?



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thomcasey
I ain't no puny human
1025/2000


Galant VR-4 org Post #: 1239839 posted 10/05/17 06:51 PM     Remind Me!  Send Private Message   Edit Post      
No oil in the plug holes.

The MAF plug that I need to wire in (haven't yet) is on my son's VR4. Mine is original so it is all connected correctly.



Thom
1991 GVR-4 1025/2000 (PTE 1200's, 16g, DSMLink v3, gm-maf, eagle/ross, .020 over, 272's)

Posts: 669 | From: Indianapolis, IN | Member Since: 09/24/14 | IP: (68.45.230.24) | Report this post to a Moderator

iceman69510
Turn Right Racing
855/2000
828/1000


Galant VR-4 org Post #: 1239840 posted 10/05/17 08:19 PM     Remind Me!  Send Private Message   Edit Post   
Nevermind.



91 VR4 855 Nile Black
92 VR4 828 Belize Green-Daily driver status
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