I been on vacation for 5 days. Whne I tried to start the truck, it would not idle. It starts fine and then dies. You have to keep you foot on the pedal to keep it going. Only after it warms up for 5 to 10 minuters will it idle.

There is also has a sound like something is coming on anf off under the hood while this is happening. it sounds like the AC compressor, but I have the AC off.

I also have no check engine light

Any advise would be greatly appreicated.

THX
Luca

 

Luca,

Look for a vacuum leak. Has a hose popped off that could be causing this?

Regards

Jean Marc Chartier

 

Hey Luca Brazzi

I had the same problem with my 97 5.4l and had the dealership look at the truck several times. The first reason that mine was doing this was there was a hole in the pcv line and a crack on the valve itself. The other reason was the IAC had gone bad and it was possibly thinking that the tranny was in drive. The dealership told me that the reason that it takes 5-10 min for it to idle is that the computer has to re-calibrate or some other b.s. But after the IAC was changed I had no problems with the engine idle. Try to take your truck into the dealer and have them check out the IAC, vacuum lines, and the pcv. Hopefully this will help you out.

Ryan

 

I ran some dry gas through it with no avail. When I let the throttle out, the idle will drop to 500rpms and often die. If I rev it up above 1000rpms it runs and drives fine. I am suspecting the IAC (Idle Air Controller) Valve and that is what the Ford Mechanics think. The valve is $65 and I believe it is my culprit and would bet it to be yours too. After this episode with my truck, I did some posting and searching on this board and discovered MANY 97-current F150's run into this problem. Mine just happened one night out of the blue when I was half way home from work. I am having new tires installed and the problem fixed as I type. If you would like I could update you later on.

 

Just curious, do the chokes ever go bad on our vehicles??

 

These engines do not use a choke. In the TB the Butterfly is fully closed during idle. There is a By-pass valve called, in Ford terms, IAC or Idle Air Control. What it does is allow air to flow around the Thottle Body when at idle. The PCM controls how much air flows around by sending current to a solenoid to open and shut a spring loaded plunger. This valve/plunger will eventually get coated in soot and carbon and needs to be cleaned. The Dealer may spray some cleaner in it but at $65-70 per hour it is cheaper to replace it. For the DIYer it is even cheaper to remove it and clean it yourself.

Regards

Jean Marc Chartier

 

$150 later and my problem is fixed. Some how, a freaking penny ended up in the hose of my FIPK between the silencer box and IAC and sucked flush against the IAC. This would not allow any air flow and burnt up the IAC. I feel like a dumbass cause I installed the FIPK but had/have no clue why/how the hell a penny ended up there??

 

I had the same problem. At first I thought it might have been the tps. I took the Throttle body off and sprayed the butterfly with carb cleaner. Never happened again.

Very easy to do.

 

I had this problem. Check the radiator hoses going into the firewall. I had a slow leak and couldnt find where it was coming from until the hose blew. What a mess. If this is the problem, you can save yourself that $65-70 per hour and just fix it yourself.

Good luck