Hopefully someone here will know what I am talking about, so here it goes. Every so often when stopped at a stop light with the truck in gear and my foot on the brake pedal my engine will surge from idle (from about 700 rpm's up to about 1200-1300 rpm's and then back to normal). I took it to the dealer once, but they were of no help, couldn't recreate the problem. I have not been able to link it to anything, it has happened when warm, when cold, with and without the a/c turned on, etc. It has been very sporadic. I have a 2001 5.4L with no engine mods. Has anyone else experienced this or know what may be the cause.

Thanks in advance for the help. Let me know if there is more information needed to make a better diagnosis.

 

I would check the voltage at the TPS (throttle position sensor) it may be out of wack. Do a search on the subject.

 

Ask Raoul about the IAC... hammers....flight recorders....

 

Yeah I know exactly what you mean!!! After accelerating, and I stop, this loud humming sound starts, the truck kinda shakes...but when I rev the engine it goes away....but if I leave it be....it almost stalls....I have an aftermarket air filter and I thought it was that but I put that in a long time ago...so I dont think its really that...I have the 4.6L v8....its getting worst too...I was going to take it to the dlr but it doesnt always happen...I thought it could be the trottle body or throttle position sensor...what should i do?? My warranty exp in dec!!!!