well, i got all my CEL lights fixed and car is relearning everything from the 1 hour battery unhooking but now it seems like the car just wont idle. Even before with the o2 sensor and misfire codes it stumbled after it was idling for a period of time untouched and now it does the same thing just not as bad, well actually it shut all the way off just now so its bad enough. Doesnt matter if the car is 100% cold or you turn it off and go in the store for a soda and come right back out, it will stumble when you start it up and leave it idle for a period of time (more than a minute).

I have checked ALL the vac lines and sensors around the throttle body and everything seems fine, ive even put in a new tps sensor which didnt help anything. Im begining to think that the cold weather has messed up my slight tune that i had done about 4 months ago making me lean out and stumble maybe? Any tips guys?

 

post your tune and a log, it could be adaptive spark is dropping timing too much. i doubt its fuel related, your ltft/stft will allways level you back to 14.7 (as long as your in closed loop).

 

If you are still using a MAF, you may want to rescale it, its probably off by a large amount. Unhooking the battery reset the fuel trims, and if they were large, it may take some time for them to relearn, which is probably why its stumbling after the battery reset. What O2 code were you previously getting?

Also, if you're using HPT, make sure your minimum pulse width isn't much larger than 2ms. Same goes with the Short Pulse adder table.

 

i do not have the HPT log at all, i got tuned by someone privately and it was running perfect until a couple weeks ago randomly, i got this stumble before the battery was unhooked also. I would think its leaning out after it stumbles, sometimes it catches itself and then its fine though.

 

Does your wideband stay pegged rich or lean, or is it sweeping in idle?

 

seems like it starts in ideal and then when it first starts to touch the rich side it goes to the lean side and catches itself and either stops doing it or dies