Jdam8139

Just got P1681 and P2135 resulting in limp mode. At the time I was trying to dial in the MAF, so I put it back on VE only and it ran rough but still ran. I don't think its the TB because then it would've run the same off the VE table.

Anybody got any clue?

Chevycobaltss3

iTrader: (2)

Reset trims within maf and look at trims... But those codes are prone for limp mode lol

Jdam8139

Yeah, I tried that. I reset the trims earlier and it still did it. So I reset the trims then warmed the car up in VE, turned it off, then started it back up with a normal blended tune and it ran decently until I turned it off again.

Chevycobaltss3

iTrader: (2)

Are you tuning in open or closed. And what are trims saying when logging. And also commanded Afr.vs.actual

Jdam8139

I WAS trying to drive in closed loop last night when it happened the first time. So I switched it back to VE open loop and it came out of limp mode long enough for me to get home. I warmed it up in OL today and once it was at 176 ECT, I shut it off and tried to run it in CL again. I had to reset trims to get it to actually run. Before I reset them, LTFT were like -20, but STFT were like +14. I reset them and drove gingerly and it ran alright. While driving I logged trims a few times, thinking the MAF could be the problem. I changed the MAF numbers and it ran a little better, so I left it.

AFR error was super rich the first time it went into limp mode. Then when I switched it back to VE, AFR was from 13.5-15.0, which I didn't think was THAT bad. Now AFR is super lean unless, of course it's in limp mode, then it's like spot on.

I'm thinking it might have something to do with my meth nozzle being too big. I switched when I was at the track because I felt like the one I was using was too small. But I just went out and took off the TB and there was a very small pool of methanol in the bottom of the TB and a whole hell of a lot of condensation on the back of the throttle plate. Problem is I didn't bring any of the smaller jets with me from Charleston, so I just disconnected the enable line to the controller so it won't spray at all.

I'm going to order a new TB and a new pedal assembly right now and overnight it so I'll know if that was truly the problem tomorrow...

Here's the log from startup and idle when it went into limp mode:



I think it might actually be the TB/TPS because the desired ETC bounces all over the place, and it's never been that bad.