My 97 hx sohc idles up and down between 1000rpm and 2000rpm when in neutral after driving it. I've taken off the IACV and cleaned it twice. Everytime I clean it the car doesn't idle, but after going a couple of miles its starts idling again. Do I need a new IACV? Any suggestions on what else it could be??

 

Check coolant level in the radiator (with engine cold). Make sure throttle cable goes slack when no one is pushing the gas pedal. Check for other vacuum leaks. You may have the FITV on the thermostat, it is plastic and prone to break. If everything seems OK, you may be able to reduce the idle by closing down the air screw in the throttle body.

 

Thanks for the info I will try your suggestions.

 

1) Make sure there are no air bubbles in cooling system.

2) Take a paper clip to pull any error codes. Even if the CEL isn't on, you should check for codes anyway. I had the exact same problem with you and it wasn't until I pulled codes did I find out that the brand new IAC valve I installed was defective. I got another new one but from the AutoZone Duralast line ($160) to finally fix the issue.

 

Coolant level is fine, no vaccumm leaks. I'm thinking that it might be the FITV. Funny thing is that I just changed the spark plugs and looking at the old ones they were pretty burnt. When I first started the car after I changed the spark plugs the rpm went from 15000 to 500. When I drove the car my car still idled higher then usual but not as high. At first it was going from 1000prm to 2000rpm, now its going from 1000rpm to 1500rpm. Ultimately I think that I have to change the IACV. Another question is there supposed to be some type of liquid coming out of the IACV when I disconnect the hoses that are attatched to it? It looks like coolant.

 

The old spark plug is on the left and the new one is on the right.