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?

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

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

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...