I have a f 150xlt super cab 4x4 4.6 130000 milesliter any how when my truck warms up and is idling at 750 rpm run it on the road stop at stop sign the rpm go down to about 250 rpm then tries to go back up to 750 or a 1000 it stalled out a few times any idea what the problem could be? It runs good when i first start it up.
Thanks in advance

 

Vacuum leak

 

Update brought the truck to the the garage it was the Idle Air Control (IAC) Valve cost was $295.00

 

Part is $75 or so, I suspect you paid $75 - 90 for hookup to computer, then part, and labor. On a car I had it was a 10 min job, code was thrown so I knew what it was.

 

I suggest finding out what it is,then buying it somewhere else and fixing it yourself. Stuff like that is a 20 minute job with basic tools,just for the future. Take coils for example,the dealership charges $80 a coil plus about $100 install,when you can buy a proven set of 8 from amazon for $60 and its only 1 bolt and one plug to pull out. 5 minute job all day every day

 

If Torque Converter is not releasing it could stall the engine. Check and make sure all brake lights are working. Idle Air Control Valve can be cleaned. The EGR valve could also be leaking exhaust gas on your intake on idle.

 

update the other was using my truck it was doing the same thing brought it back to the garage last Thursday the (5th) called Saturday(7th) he said the truck died on the road towed it back to the shop said the truck started up when i talked to him he said it was a fuel issue. I also told him the 5 amp fuse keeps shorting out the it controls the (fuse # 29 5 amp Autolamp module, Transmission
overdrive control switch, Centralsecurity module, Beltminder)

over drive and door locks i do not know if that is part of the problem or not

 

dang I paid $50 for my iac valve and it took like ten minutes to change them out. I'm so in wrong business.

 

I can't decipher what you meant to say in the first part of this post.

As for the fuse blowing, remove the plastic by the shifter. You will see the frayed or broken wire.

This wouldn't be related to stalling. As they told you, the IAC is common cause of bouncing RPM and stalling.

It could be the fuel pump if the IAC didn't fix it. They'll test the fuel pressure and let you know.

 

With that many miles it could be cat. converters. They don't live forever. Mine totally failed, stopping any highway driving, at 230,000 miles. Amazing the difference new ones made.

'97, 4.6, Scab.