Hey guys sorry for the following vague description of a problem but I'm hoping someone can help me out. For a while now my truck (2004 F150 STX 4x4 RegCab ShortBed 4.6L) does this weird thing where when I apply my brakes to come to a stop, my rpm's jump up and my truck tries to purge forward. Well today (just a few minutes ago actually) while I was parking my truck on my street I eased on the brake, then my rpm's sky rocketed (I don't have a tach, going off of sound) with my truck trying to launch forward. So I stepped on my brakes harder and lost power brakes, power steering, my dash lit up, then my truck just kind of slowly dropped rpm's until it died with a "check gauges" light on. Any ideas?

 

Just to add more to this, the problem still exists. I've come to the conclusion that it may be the idle air control motor. But what's tough is the problem doesn't exist all the time. Truck tries to launch forward maybe 1 in every 10 stops. And 1 in every 20 now it'll just stall (which is odd to me, with an automatic transmission, but it'll be in gear and just die at a stop).

 

I'd start with the TPS and the IAC. Clean the MAF, what code is it throwing?

 

While you're in there, go ahead and pull the TB and clean it as well. Sounds like there is alot of gunk built up in there and not allowing the TB to open and close correctly.