Lately when I start the truck in the morning the fast idle does not kick in. I have to hold the throttle at 1200 rpm or so for a minute or so then it kicks in. It does this 3 out of 5 times. If I let off the gas it dies. I've also noticed my mileage dropped to 12 from 14.5mpg. Most of my driving is highway. I'm letting the truck warm up for under 5 minutes, Virginia weather is generally warm (above 35 degrees most mornings). I will do a tune up this weekend and clean the air filter, plan on putting in some seafoam also.

Truck is 96 f150 with a 302, 189k on the clock.

Any ideas? Anyone change the IAC lately and can say how difficult it is or give any pointers?

Thanks,
Randy

 

Pull codes. That is the best way to diagnose issues with these trucks.

And for the record, the IAC is one of the easiest things to change. Two bolts and a plug. That is all. If you have to change it, get one from Ford. I went through 3 parts store brand IACs before getting a Ford, and it is still on the truck.

 

If you were closer to the Hampton area, I'd come look at it. I can fix it, whatever it is. Hard to tell someone "over the phone" as I like to call it. You could do that in the 70s and 80s, just not now. Could be simple as a bad IAC. Try to clean it and see what happens. If it helps, replace it with one from Ford only. Check for any vacuum leaks also. Check the timing. As these things get old, the timing will fall off due to chain stretch. Just a few things I hope will help.

Robbie

 

Since when is VA Beach no close to Hampton? When I lived there it was all considered Hampton Roads...

 

It's not close, because you have to go through a tunnel that is ALWAYS backed up. Besides, I'm another 20 minutes away from Hampton, but nobody knows anything about Poquoson, so I say Hampton. That gets you in an area that is heard of.

 

Robbie,
why would the timing effect the cold start idle or even a vacuum leak. After it runs a minute or two with me holding the throttle the high idle kicks in and then she runs fine. After it completes the warm up cycle it idles fine. This only happens when the trucks cold. I appreciate that you volunteered to help and still may take you up.
Thanks