I have a 92 stealth es 3.0 dohc (NON turbo) std trans last time i had the car running i ran it out of fuel gage dosen't work then it was ok for a few weeks car started to run like crap off of idle farting 7 poping so i parked it for the winter and now have it out again put a new fuel pump in started it up and it runs great at idle if you go and take it off idle it revs up & down like a switch on-off on-off on-off if you really try and rev it if farts pops back fires and just up & down like someones switching it on-off made a rig to check fuel pressure at the rail it has just over 40 psi @ idle and manifold vacum @ idle is a steady 21" i put a used fuel regulator on no differance i also have a used unknow conditon crank angle sensor put it on same thing if you hold the gas pedal down a bit and let it rev up &down for awhile thecheck angine light will come on i think probaly a multiple miss fire code i would guess any one have any thoughts?

 

i has an issue with my car running rough and come to find out it was one of the ignition coils was bad. it had a little crack in it and was causing it to jump a spark to the coil next to it.