I went to start my 1999 F150 this morning, and it would not idle.

Went out and bought an IAC for $67 and replaced it.

Works fine now.

BTW - The old IAC was really cruddy inside.

 

You lucked out. It could have been a number of other parts and reasons.

 

Paul,
I would rather be lucky than good, any day! Nice job on the parts purchase.

 

I'm glad that you fixed it with the IAC. This typically fixes the problems with idle when cold.

I've been having trouble with intermittent idle problems after it is fully warmed up. I had the injectors professionally cleaned, replaced the plugs, cleaned the throttle body and cleaned the IAC - still has the problem. I finally replaced the IAC, but it didn't fix it.

So, I'm now wondering where to look... I know that some folks have suggested the PCV and it's hose, but I didn't thing this is it because the problem only occurs intermittently, and only after it is warmed up and sitting in gear when stopped (at a light or in traffic). A quick slip into neutral and blip of the throttle almost always corrects the rough idle.

So, I'm still stumped and looking for a solution...

 

W2aew,

Try cleaning the MAF with Throttle Body Cleaner or Electrical Contact Cleaner. It typically gets fouled over a period of time. I did that awhile back when iwas having similar problems. Worked wonders. The next thing would be to check the vacuum hoses for cracks.

good luck

Eric Bender

 

whats an iac? sorry unfamiliar with these shortened discriptions.

whats the word for that?? i forgot................schools been a long time gone.

 

idle air control valve