tbi engine oscillating idle, when cold

[franklinj]

1989 sub, idle up and down at a cold start, seems to disappear when warmed. also, after shutdown at operating temp. , come out to start within 15 minutes and it doesnt want to operate at all till "warmed" up. replaced all sensors,iac,temp,egr,map,pcv,fuel regulator, nothin doin. any assitance?

[4onFloor]

have your fuel pressure check while the engine is cold, if you haven't already

[Fireplug]

Clean out your IAC valve on the TBI and clean the TBI unit inside and out
Check you ign coil for any crud built up on the post

[Dr. Eagle]

Originally Posted by 4onFloor

have your fuel pressure check while the engine is cold, if you haven't already

I think you are on the right track with that reply. Look for a fuel problem, clogged filter or weak fuel pump. Low fuel pressure when cold will manifest itself just that way since the engine is run richer by the computer when cold...