Low Idle after cleaning IAC and Throttle Body

[nfazer]

Hi all,

I've got an small issue that I'd like some opinions on before I start throwing parts at my truck - '96 4.0 stock Ranger. I cleaned the IAC and throttle body this weekend using throttle body cleaner, and after I put it all back together, the truck idles very low, usually 450-500 RPM and rough. It sounds like it wants to die, and does once in a while if I leave it idle long enough. If I push on the throttle, it's fine. It also drives down the road perfectly fine, it only has idling issues when I am almost to a stop or at a stop (when idle is usually lowest).
Also, the battery guage fluctuates quite a bit while the idle is low/rough. I cleaned both battery terminals and had no improvement.

I did some quick testing and unplugged the MAF while the truck was running and the truck shut right off, so I'm assuming my MAF is working. I also didn't touch anything in that area; I took the rubber intake right off and before working with anything else.

At this point I'm wondering if my IAC sensor/valve is shot. The IAC also does not appear to have a gasket - it's metal to metal onto the intake.

Any other ideas?

 

[nfazer]

Well, since it had trouble idling and nothing else, I figured I'd try a new IAC valve - fixed it right up! Idle's normally now. For those who may have a bad one and are thinking of cleaning it, I was able to clean mine once with success, however this time cleaning it may have done more hard than good.

 

[asalasch]

Great Info, thanks

 

[Abbondanza]

I had the same results after attempting to clean my IAC, very poor idling. Replacing the part cleared the poor idle for me as well.

 

[koda2000]

one thing you can try before replacing the IAC valve, is to remove the little cap on the side. underneath, inside a hole, you'll see a small filter. carefully remove it, clean, dry and replace it. this is where the IAC breathes from. perhaps your attempt to clean the valve clogged the filter. it may not help, but it's free to try.