hey everyone, i have a 92 civic, and i know older civic have had this problem but i just want to ask your opinion, now when i start the car, sometimes it will idle like normal, but then sometimes it will go up and go down then go up then go down, kinda lik im reving but im not, im just sitting there. ive narrowed it down to a weak vaccum leak or a bad maf sensor, what do you guys think?
-PinoyCivic

 

Vaccum is a good start to check out. Take carburetor cleaner and spray around the intake manifold area where it connects to the motor and throttle body area where it connects to the motor. See if the idle changes. If it does, theres your problem. Also check the IACV behind the intake manifold, clean it out. Bleed your coolant too. Sometimes the problem is TPS sensor, check it and if thats the problem re-adjust it.

 

iacv, 70% of the time i would bet its the same for urs, also are u running the correct ecu for ur car?