Today I pulled up to a stoplight and the car simply forgot to idle. The rpms dropped like they normally would except that the drop didn't stop at idle, but instead continued until the car was off. This continued until I got to where I was going. So I parked the car and walked around at a car show wondering what the hell was going wrong with my idle. I go back outside and start the car, and it idles perfectly. I noticed that the water temp was in the 160's. Next stop light water temp was in the 170's and the car wouldn't idle, it would just die like before. So i sat in quite a frew lights so the water temp got up to 190 degrees, and the car would hold an idle but it was really rough. Then I parked the car for a few hours and watched a movie, came out and started it and it idled perfect, as soon as the water temp got up to the 170's it would get an extremely rough idle but this time it held it, almost sounded like it was missing or something. basically what I figured out is that it idled while cold and hot but not inbetween... I have a pfc and that's one of the few things that I think could be messing with the idle? but I don't know why it would randomly start being screwed up? anyway hopefully somebody can help... thanks in advance and sorry about the essay

Have you ever changed any of the settings in the PFC? There are various idle settings that could cause that and also some coolant temp settings that adjust the timing with different coolant temps. Have you messed with any of that?



If it just started doing this all the sudden for no reason and you didnt mess with the PFC I'd prob look at something else.



Is it missing in high rpms or anything like that?



If you take off nice and easy does the roughness go away as soon as you start moving? or does it stay kinda rough up to maybe 2-3K rpms?



Later,

STEPHEN

i've been playing with the pfc, but it didn't start right after any of the changes, i actually started changing settings to try and fix the problem. the only thing it can't do is idle every once in awhile, there are no other misses or any sort of roughness in the power curve. It's always kinda stumbled in the upper rpm range, but I had figured that was because the ignition wasn't powerful enough.