Mysterious rich LTFT's

[Bob-o]

Thought I'd post in here so the people who tuned me can see/guide me through with my issue.

OP is posted here: EWG GTX3071 rich at idle

Pretty much, car runs rich and is throwing "Rich at idle" code.

Overall behaviour of the car is quite abnormal, and i'm looking for some insight before I start throwing money at the thing.

Idle and WOT logs are in post #27 of my other thread

Here are some logs from tonight.

114 is 3rd gear
115 is idle

[MS3Shadow]

#27 post is merged into OP. For easier viewing.

[blackms3_71]

I haven't read the other thread but have u checked maf wires? a bad maf sensor itself? egr, egr pipe on block and egr pipe to mani not leaking? no cracks in ex. mani? injector seals? maf cal good? vac lines? bov? pcv? pcv plate? air straighter in the intake. reflash map?

[Bob-o]

Originally Posted by blackms3_71 I haven't read the other thread but have u checked maf wires? a bad maf sensor itself? egr, egr pipe on block and egr pipe to mani not leaking? no cracks in ex. mani? injector seals? maf cal good? vac lines? bov? pcv? pcv plate? air straighter in the intake. reflash map?

I noticed my AFR's change when i wiggle the MAF wires; maybe this is a cause?
EGR has primary and secondary blocks.
Exhaust mani and gasket appeared okay when I had to replace turbo o-ring.
Injector seals were done last year (CP-e).
MAF cal was done by Lex, and checked out when we initially did the tune.
There is no air straightener in the intake

I am going to redo the boost leak test with soapy water and make sure I didn't miss anything.

@Lex; I noticed the issue initially occurring after my wastegate stopped sealing, and had to be replaced. From there the o-ring on the compressor housing was found to be not sealing, which was then replaced. After that I thought everything was good, and fuel trims improved for a little bit, but over time went back into the -20% range.

My cold starts were also stable and strong during that time, then eventually got a little more bumpy, and even gave a random misfire code once. Perhaps plugs need to be looked at?

[Lex]

Is this a new development? If so when did you start noticing the issue?

[Lex]

The car has been checked for any vacuum and boost leaks I assume. Plugs should definitely be looked at.

[blackms3_71]

It is the maf wires then. I had this issue on my car. I would get crazy negitive trims and really rich afrs on wot. So rich that the car would stutter and have black soot out the exhaust. Move the wires around and the car would have a noticeable change in idle and everything would be back to normal.

I got a pigtail from a junk ms3 and everything has been fine ever since. I would deff fix this issue first b4 you go crazy with other things as i have seen this personally and it lines up with ur issue.

Also a air straighter would be a good idea

[blackms3_71]

Also today on my car i am getting -18 stft at idle and idle only. Ltft are at -.94 yet it wont learn the ltft even on a reflash and idle for 20 mins. I dont know what that means. I checked for leaks by boost test and sprayed carb cleaning on all hose and gaskets. Check everything possible.

[Bob-o]

Originally Posted by blackms3_71 Also today on my car i am getting -18 stft at idle and idle only. Ltft are at -.94 yet it wont learn the ltft even on a reflash and idle for 20 mins. I dont know what that means. I checked for leaks by boost test and sprayed carb cleaning on all hose and gaskets. Check everything possible.

If you just reflashed, you probably need to drive around a bit for the car to learn the LTFT's, no? Also, STFT's come secondary to LTFT's i thought? I understand the LTFT's are build from STFT's, but they are much more subject to change and can swing up and down from moment to moment?

I am very curious to see if addressing the MAF harness will fix the issue; problem is I'm working out of town, and not at my car

Reading the TSB's for this issue, they indicated it was the black ground wire that caused all these issues. Should this be the only wire I do? Or would all the wires need to be cut, stripped, and repinned?

[blackms3_71]

Originally Posted by Bob-o If you just reflashed, you probably need to drive around a bit for the car to learn the LTFT's, no? Also, STFT's come secondary to LTFT's i thought? I understand the LTFT's are build from STFT's, but they are much more subject to change and can swing up and down from moment to moment? I am very curious to see if addressing the MAF harness will fix the issue; problem is I'm working out of town, and not at my car Reading the TSB's for this issue, they indicated it was the black ground wire that caused all these issues. Should this be the only wire I do? Or would all the wires need to be cut, stripped, and repinned?

You are right about the trims but what i noticed with my car is that ir learns the trims within 2 miles of driving. And they will slightly level out within the next 10 but its basically spot on within 2 mile. I tried disconnecting the battery and re flashes and it still learns it that fast.

Yes ltft are based off stft but when my ltft are -.94 with stft -17 the car should pick that up pretty quick. 2 day it learned some and went to -10 ltft and then out of no where it went to -.16 ltft like if some how it got reset? Idk whats going on there. Going to check for leaks again and if nothing try adjusting the maf cal a bit.

And yes i read it was the black wire also. I ended up with a new pig tail so i cut and spliced all new wires. Now when i wiggle the wires i get nothing to happen on the ap which is good. I also have a 2nd maf sensor i may try out and see what happens.