Bruce-Wayne

I just bought a 94 Civic Lx about a week ago. Ever since I have had the car it has had a pulsing idle. I have done some research and found that a lot of the time it's the iacv or the fitv. I have cleaned both of them. Upon cleaning them I started the car and it seemed to have helped a little. But when I got in the car later to drive it, the problem was just as bad. It only pulses when the car is sitting or when I push the clutch in. While I am pressing on the gas it doesn't seem like there is anything wrong.. I do smell an exhaust-like smell as I drive though. I have also read that the problem could be a vacuum leak or that the iacv/fitv might need to be replaced; maybe even the sensors? Any other opinions on the matter? How would I go about checking to see where the problem lies before I go spending money on unnecessary parts? I appreciate any feedback. Thanks!

genosbro

If your Check Engine Light is on, Get a CEL Scan and post what codes your car is throwing first.

You can try unplugged your IACV before you turn your car on. Idling with the IACV unplugged should either drop your RPMs drastically or stall out your engine. If it does do this your IACV should be fine.

I would check for vacuum leaks, their are tons of safe / unsafe ways to do this. Look up on youtube on how to check for vacuum leaks. But please be careful it can be dangerous is some cases. (Hot engine)

If any sensor would be effecting your idle it would the Throttle Position Sensor. If you have a MMS Scanner check to see if your TPS is getting the proper voltage and proper voltage during ignition use. Check out this video
I did this myself last night and it worked perfectly and actually saved me alot of time and money!!!