mvvette97

iTrader: (18)

I've been after this problem all summer and can't figure out what the problem is. Cold start is fine and driving is fine. After car is warmed up if I turn the car off for a bit and then start it up to take off here is where the problem is. It will start and idle fine but just as soon as I take off it will start to miss very bad. At the same time it will pull huge amounts of fuel from bank 2. It will do this for about 10 seconds or long enough to shift from 1st to 3rd then just snap right out of it and run fine. After that it doesn't matter how long you drive it because it will run fine till I turn it off again and restart. Then it will do it all over again. I replaced the O2 on bank 2 and no difference. Just a while ago I changed back to the stock injectors and it still does it. I logged it and it's number 6 that will misfire badly. Like I said it will only do this after a hot start and only last for a few seconds.. Any idea what could be going on here? It just started doing this at the beginning of summer. Just has me baffled since after the spell it has it will start runing fine again with no misfires.

white01ss

iTrader: (37)

I think you're running into a hot-start issue. My understanding, is that a hot engine that has been off for a short time has more friction than just turning it off and immediately restarting. Even if the coolant temp is within operating temperature for closed-loop, the PCM will stay in open-loop for a a short-time after a restart and the car is running solely off the MAF/VE tables until that period expires. I would make sure that the MAF calibration is giving enough fuel in those ranges where it stumbles. Also, there are tables for hot-start enrichment that handle the duration and amount of enrichment, but you shouldn't need to mess with those if your open-loop fueling is right on. Good Luck.