i have a 99 civic ex sedan with a 95 integra ls swap. (OBD1) ok here is my problem when i am idling ok when i stop at a traffic light, or stop sign my car (RPM'S) rev. up and die down!!!!!!!!!! can a exhaust leak between the header and down pipe cause this? or if not what else should i be looking for? thanks

 

an exhaust leak wont cause an idle problem. unmeter air entering the engine is what causes the idle to surge... your iacv could be bad or you could have a gnarly vacuum leak.


iirc when you take off your intake there should be 2 holes on the back side of the throttle body on the inside. i think if you cover the top one with your finger and the idle fluctiation ceases then your iacv is bad. you could try cleaning it

 

thanks you replied to my other post. about the valce clearance. i gaped the intake side to .005 and the exhaust side to .008 and then from there i just messed with the dizzy and BAMM!!!!! it runs like a top. idle problem is right at 900 (RPM) thanks....

 

try unplugin your o2 sensor and if the car runs fine replace it.