Runs better with MAF unplugged
10-31-2008, 07:41 PM
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Runs better with MAF unplugged Including links to pertinent threads I have going in FL members section, and Newbie Tech.
https://ls1tech.com/forums/new-ls1-owners-newbie-tech/1008394-holding-rpm-shift-points-throttle-release.html (holding rpms at shifts and upon throttle release)
https://ls1tech.com/forums/florida-members/1010638-looking-brevard-shop-turn-off-p1133-p1153.html (looking for help gettin p1133 and p1153 tunred off)
A light finally went on thanks to some replys from forum members here, on both issues, I am addressign the performance related ones here.
Doc from EFI Alchemy responded and said its gonna be the MAF or MAP since car runs better after a PCM reset (I have been doing the 2 fuse pulls, turn key to on method). Exchanged PM's with another member and he had the observation that, since it runs well after a reset, and then gets worse over time, that tells me 2 things, 1. Base tune is not horrible, 2. The tune is being driven worse by bad feedback (this explains to me why it gets worse over time).
So, I just got done going for 2 drives, one with MAF unplugged and one plugged in. Bu unplugged I mean I took the 3 wire clip off and let it dangle.
UNplugged:
I heard and felt the difference. Throttle response was much better all thru the range, i couldnt go WOT for more than half a sec, no time to take it out of town, and it halloween people out and about and all that. Car felt like it had big giant nuts. LIke it always wanted to go faster no matter what speed I was at. Shifts were good, where they were supposed to be, etc etc. It did feel occasionally slightly rougher, just off idle, for a fraction of a second. Also idle was a little odd for about 3 secs the first time I started it, the other 2 times it was already warm and i noticed no change.
Plugged in :
It was quieter, was back to a dog at part throttle. Noticed a few more rough spots. Noticeable power difference. WOT response bogged then wanted to go (by the time it wanted to go, I had to back out, see above).
I expected to see a light pop when I unplugged the MAF, but it hasn't yet.
The idle speed has never changed. About 850 when I first start it if it is completely cooled down and ambient, within a few minutes or after it has warmed it sets at 500rpm.
I think this tells me, it is the MAF, not the MAP, and, I may still have a intermittent problem with the 02 sensors. I can not afford a full tune right now, so I need to replace with a stock MAF (what is in the car now). To that end I might not be able to swing an alternator and a MAF, for the next few weeks, would it be ok to drive around with MAF unplugged ?
In absence of scanner I was going to fill up with gas, drive 100 miles each with MAF unplugged and plugged, and compute gas mileage, just to get some more data.
Chewie
https://ls1tech.com/forums/new-ls1-owners-newbie-tech/1008394-holding-rpm-shift-points-throttle-release.html (holding rpms at shifts and upon throttle release)
https://ls1tech.com/forums/florida-members/1010638-looking-brevard-shop-turn-off-p1133-p1153.html (looking for help gettin p1133 and p1153 tunred off)
A light finally went on thanks to some replys from forum members here, on both issues, I am addressign the performance related ones here.
Doc from EFI Alchemy responded and said its gonna be the MAF or MAP since car runs better after a PCM reset (I have been doing the 2 fuse pulls, turn key to on method). Exchanged PM's with another member and he had the observation that, since it runs well after a reset, and then gets worse over time, that tells me 2 things, 1. Base tune is not horrible, 2. The tune is being driven worse by bad feedback (this explains to me why it gets worse over time).
So, I just got done going for 2 drives, one with MAF unplugged and one plugged in. Bu unplugged I mean I took the 3 wire clip off and let it dangle.
UNplugged:
I heard and felt the difference. Throttle response was much better all thru the range, i couldnt go WOT for more than half a sec, no time to take it out of town, and it halloween people out and about and all that. Car felt like it had big giant nuts. LIke it always wanted to go faster no matter what speed I was at. Shifts were good, where they were supposed to be, etc etc. It did feel occasionally slightly rougher, just off idle, for a fraction of a second. Also idle was a little odd for about 3 secs the first time I started it, the other 2 times it was already warm and i noticed no change.
Plugged in :
It was quieter, was back to a dog at part throttle. Noticed a few more rough spots. Noticeable power difference. WOT response bogged then wanted to go (by the time it wanted to go, I had to back out, see above).
I expected to see a light pop when I unplugged the MAF, but it hasn't yet.
The idle speed has never changed. About 850 when I first start it if it is completely cooled down and ambient, within a few minutes or after it has warmed it sets at 500rpm.
I think this tells me, it is the MAF, not the MAP, and, I may still have a intermittent problem with the 02 sensors. I can not afford a full tune right now, so I need to replace with a stock MAF (what is in the car now). To that end I might not be able to swing an alternator and a MAF, for the next few weeks, would it be ok to drive around with MAF unplugged ?
In absence of scanner I was going to fill up with gas, drive 100 miles each with MAF unplugged and plugged, and compute gas mileage, just to get some more data.
Chewie
Last edited by ChewieFL; 10-31-2008 at 08:09 PM.
11-02-2008, 10:23 AM
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I had cleaned the MAF twice during this period. Once before the catback change, and once after refreshed K&N and Seafoam. Back to crapness soon after. That's the frustration, it will be running good, I'm thinking sweet, that got it....... then
.
I went down to NAPA and got a new MAF, $100 less than the dealer, and for about 50 more than a reman. Got a OEM replacment for my vehicle. I am not descreening this one, old one was.
I reset PCM via fuse method, drove to Advance (NAPA doesnt scan or clear codes, but they will sell you a scanner. Damn Hippies). Only code in the system, was p0102 low votlage MAF input. Since I was driving for 2 days with MAF unplugged, I figured that was it. Cleared it. Before I left the Advance I reset PCM again, I wanted to start out, with no codes, and untrimmed, as previously, the PCM reset fixed all my issues, albeit temporarily.
This time... well it seems like there is definitley "learning" happening. It will seem perfect for a moment, then a brief period of shat for low end throttle response, then ok again. I did notice when I had everything disconnected down to front of TB there was the hole in TB plate, about 3/32 it looked like. This has been there as long as I have owned car.
It is definitely breathing better, I can hear that whistle at speeds and RPM's that I did not before. When it is running right on, it has a louder stronger exhaust note. I needed something to take my mind off of things so, I finished the !AIR mod, dropped the pump, and 2 hoses, left fuses in.
In the middle of this I have noticed at least one of the motor mounts is bad, from watching it torque over when I move throttle, perhaps a hose had been jarred, but I cannot find a vac leak, see it, hear it.
I tested the heater circuit for the new 02's by turning key to on, and yes they do get warm. Nervous about the exposed wires on the back of the BOSCH though. Thinking of getting some tape, grease, larger rubber hose (for a very temporary mold, and some high temp RTV to make a "boot" for that area in back of the plug.
It did stumble on idle once, and a few times of holding RPM's at shift points, about 80% of the time shifts seem solid, and 20% kinda mushy. Is there any sort of standard for how long, or how many miles you need to drive the car before it should be "back to normal" after a new MAF and PCM reset ?
Chewie
.I went down to NAPA and got a new MAF, $100 less than the dealer, and for about 50 more than a reman. Got a OEM replacment for my vehicle. I am not descreening this one, old one was.
I reset PCM via fuse method, drove to Advance (NAPA doesnt scan or clear codes, but they will sell you a scanner. Damn Hippies). Only code in the system, was p0102 low votlage MAF input. Since I was driving for 2 days with MAF unplugged, I figured that was it. Cleared it. Before I left the Advance I reset PCM again, I wanted to start out, with no codes, and untrimmed, as previously, the PCM reset fixed all my issues, albeit temporarily.
This time... well it seems like there is definitley "learning" happening. It will seem perfect for a moment, then a brief period of shat for low end throttle response, then ok again. I did notice when I had everything disconnected down to front of TB there was the hole in TB plate, about 3/32 it looked like. This has been there as long as I have owned car.
It is definitely breathing better, I can hear that whistle at speeds and RPM's that I did not before. When it is running right on, it has a louder stronger exhaust note. I needed something to take my mind off of things so, I finished the !AIR mod, dropped the pump, and 2 hoses, left fuses in.
In the middle of this I have noticed at least one of the motor mounts is bad, from watching it torque over when I move throttle, perhaps a hose had been jarred, but I cannot find a vac leak, see it, hear it.
I tested the heater circuit for the new 02's by turning key to on, and yes they do get warm. Nervous about the exposed wires on the back of the BOSCH though. Thinking of getting some tape, grease, larger rubber hose (for a very temporary mold, and some high temp RTV to make a "boot" for that area in back of the plug.
It did stumble on idle once, and a few times of holding RPM's at shift points, about 80% of the time shifts seem solid, and 20% kinda mushy. Is there any sort of standard for how long, or how many miles you need to drive the car before it should be "back to normal" after a new MAF and PCM reset ?
Chewie
Last edited by ChewieFL; 11-02-2008 at 10:29 AM.
11-02-2008, 11:51 AM
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I have been reading alot about MAF's, changing your airflow, and how that can affect 2 things, big time. 1. Your tune (fueling, how it runs), 2. Transmission.
That is exactly what is affected.
Still confused as to why it ran so well, when I just unplugged MAF.. shifts, everything excellent.
Now that there is a brand new NAPA OEM MAF in it, it brings to mind yet more details. The lid is missing the gasket that makes it seal in the top (SLP + K&N), yet is always has been. I did change the airflow, I cleaned the filter, it was black, jet black and nearly clogged along the half that actually flowed the air. Prev owner did the free ram air mod, cutting up front of airbox and bottom, hella airflow (but then it doesnt actually pull it through the entire surface area of the filter just the half towards engine).
I cleaned the MAF with proper cleaner, I noticed it was a BEEotch to get out of SLP lid, even though there was no seal, just MAF Housing sliding into hard plastic lid ... how the hell can that seal correctly, I question the need for the hose clamp on it even, it sure as hell isnt clamping that plastic ?
Changing I-pipe from 2 3/4 up to 3 " so from collectors > Y Pipe > muffler in, it is all 3 ", certainly changed airflow.
So here is my latest theory, reality check it for me please....
After the headers were done, they tuned car, with Diablosport (I believe that was the one they used). When they did that, the airfilter was either overoiled or dirty or both. I do not know if MAF was descreened before or after. So it got tuned, and drivable, then.
After changing the exhaust, properly cleaning the airfilter (took me 3x cleaning cycles), cleaning, reseating MAF (housing was so tight, assembly always came off as lid + MAF), cleaned the inside of smooth bellows, did Seafoam. Installed new OEM screened MAF. .... I need a tune to fix things, and parts are not going to do it.
Can a datalog file and a mail order tune, get me there/close, or any local FL members willing to give it a shot (I will pay for license of course) ? I'm not worried about it getting worse, we can save file(s) like it is, and reload backups right ? I am working on selling some things to pay for a full dyno tune, but just dont have the funds. Kinda had to "rob Peter to pay Paul" to get the MAF.
Should I continue to drive with new MAF in, and see what happens, or unplug it again, until I can get a mail order/full tune ?
Chewie
That is exactly what is affected.
Still confused as to why it ran so well, when I just unplugged MAF.. shifts, everything excellent.
Now that there is a brand new NAPA OEM MAF in it, it brings to mind yet more details. The lid is missing the gasket that makes it seal in the top (SLP + K&N), yet is always has been. I did change the airflow, I cleaned the filter, it was black, jet black and nearly clogged along the half that actually flowed the air. Prev owner did the free ram air mod, cutting up front of airbox and bottom, hella airflow (but then it doesnt actually pull it through the entire surface area of the filter just the half towards engine).
I cleaned the MAF with proper cleaner, I noticed it was a BEEotch to get out of SLP lid, even though there was no seal, just MAF Housing sliding into hard plastic lid ... how the hell can that seal correctly, I question the need for the hose clamp on it even, it sure as hell isnt clamping that plastic ?
Changing I-pipe from 2 3/4 up to 3 " so from collectors > Y Pipe > muffler in, it is all 3 ", certainly changed airflow.
So here is my latest theory, reality check it for me please....
After the headers were done, they tuned car, with Diablosport (I believe that was the one they used). When they did that, the airfilter was either overoiled or dirty or both. I do not know if MAF was descreened before or after. So it got tuned, and drivable, then.
After changing the exhaust, properly cleaning the airfilter (took me 3x cleaning cycles), cleaning, reseating MAF (housing was so tight, assembly always came off as lid + MAF), cleaned the inside of smooth bellows, did Seafoam. Installed new OEM screened MAF. .... I need a tune to fix things, and parts are not going to do it.
Can a datalog file and a mail order tune, get me there/close, or any local FL members willing to give it a shot (I will pay for license of course) ? I'm not worried about it getting worse, we can save file(s) like it is, and reload backups right ? I am working on selling some things to pay for a full dyno tune, but just dont have the funds. Kinda had to "rob Peter to pay Paul" to get the MAF.
Should I continue to drive with new MAF in, and see what happens, or unplug it again, until I can get a mail order/full tune ?
Chewie
11-03-2008, 08:28 AM
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Thanks DOC@EFIAlchemy and Jimmyblue ! 2 Days on new MAF so far and all is well. Shifting firm and almost where it used to. No more holding RPM's or random revving. As far as the 02 issues go, no codes again on that yet. I am using a "trick" I read about someone doing, just to turn the key on for 15 secs or so to let the heater circuit warm up the sensors, then start it up.
There are a few things here and there, where its a little off ---- sig quote incoming ---- hard to explain, I have a very sensitive, well calibrated Butt Dyno.
Fun to drive to work again, alot of stress off. I feel like an infomercial audience member "Thank you LS1TECH".
Chewie
There are a few things here and there, where its a little off ---- sig quote incoming ---- hard to explain, I have a very sensitive, well calibrated Butt Dyno.
Fun to drive to work again, alot of stress off. I feel like an infomercial audience member "Thank you LS1TECH".
Chewie
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11-05-2008, 09:59 AM
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hey those codes that you were throwing, i'm throwing them now, but i believe it's related to a change i made in my tune. i set it up to run in PE mode almost 100% of the time which seems to have caused the codes to pop up.
11-13-2008, 05:28 PM
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Did not solve all, but it helped alot. Gas mileage has improved noticeably around town, while conversely driving it hard, eats more gas now.
It still needs a full tune, which was part of the problem to begin with, which in turn was made worse by bad sensor input, and the exhaust change, and possibly improving the induction side.
My final step was resetting PCM (with fuse pull/key on method), then driving with MAF unplugged for a few days. It still seemed much better that way, of course plugging it back in, went to poop.
If you are comfortable pulling off MAF housings, you can find just the MAF part itself, is cheaper than w/housing/screen etc.
That MAF being messed up can dork up all kinds of things.....
Chewie
11-13-2008, 05:44 PM
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Chewie
Thanks for the reply, I have unpluged it and does seem to run better idle wise anyway, How do you do the fuse pull reset method ( I guess i could do a search on it) I think I will go ahead and get another maf with or without housing bacause this is very iritating..............
Thanks again
Thanks for the reply, I have unpluged it and does seem to run better idle wise anyway, How do you do the fuse pull reset method ( I guess i could do a search on it) I think I will go ahead and get another maf with or without housing bacause this is very iritating..............
Thanks again
11-14-2008, 07:36 AM
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j/k
Fuse pull... this is on a 2001, so I am assuming it is the same for your vehicle.
Under hood drivers side between fender hump and bumper, you will see 2 black boxes, lids come off with finger pushing in on a snap, then pull up. On the underside of the lid, is the diagram for the fuses, you want PCM BATT and PCM IGN. With car off, key removed, pull those 2, one is 10 amp, one is 15 amp, and one in each box. Turn key to ON position, but do not start car, wait 15 to 30 secs, Turn off, remove key. Replace fuses. Start her up.
This also resets all your fuel trims, and wipes out all the "learning".
I'll try and get some pics up later.
Chewie
11-14-2008, 07:38 AM
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11-15-2008, 07:07 PM
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The one thing that sticks out to me is that you cleaned your K&N and the question is did you re-oil it like K&N reccomends? If so, that could be the underlying cause fo your problems. The filter oil has a tendency to screw up the maf readings.
11-23-2008, 02:57 PM
#19
Well, it's one of two things, either the maf tune is off causing fueling issues, or the maf itself is deffective, which since you just switched to another new one is less likely the cause.
So my bet is your tune is off and by disconnecting the maf, you go into open loop, speed density which is better for your current situation.
So my bet is your tune is off and by disconnecting the maf, you go into open loop, speed density which is better for your current situation.
11-23-2008, 04:19 PM
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Well, it's one of two things, either the maf tune is off causing fueling issues, or the maf itself is deffective, which since you just switched to another new one is less likely the cause.
So my bet is your tune is off and by disconnecting the maf, you go into open loop, speed density which is better for your current situation.
So my bet is your tune is off and by disconnecting the maf, you go into open loop, speed density which is better for your current situation.