I've just begun experiencing a problem with my 2004 F150. This happened twice this past Saturday. While sitting at a traffic light the engine began to race. Luckily I had my foot on the brake and immediately put it in park and it settled down. I've had this truck since April and this is the first time it happened. Friend of mine has the same problem with his 2002 F150 and damn near went through a Mac's Milk. Dealer put his on the diagnostic and came up zero. Has anyone else experienced this "phenomena"?

 

Maybe. We had a guy that had a racing idle that was following a bad TPS sensor.

 

i also have a 2004 5.4L V8, and this has happen to me once about a couple of weeks ago. i wouldn't say it was racing, but when i stoped at a stop sign, it began to rev a little and move forward when i didn't have my foot on the gas. weirdest thing. i just steped on all the way down and it stoped. i thought maybe it was just slipping a little and maybe it was the anti-slip differentials working since i was on gravel, but now maybe not. couldn't tell you what's wrong, it hasn't happen to me since.

 

I don't know much about the '04-05's, but are these cable throttles, or throttle by wire? In either case, the only things that would cause an RPM change would be a sudden vacuum leak, malfunctioning TPS or pedal pot if TBW, ECM, or a possible (not likely) short.
When you do find out what the problem is, please post it. Thanks.

SL

 

I've sent a query to the witch doctors at the Ford plant that make the 5.4 L 3 vlv which happens to be the plant I retired from last April. Hopefully I can some help from those guys. In the meantime I've got an appointment with the dealer on Monday. Yahoo! yeah right!

 

When my 99 5.4 did that a new IAC fixed the problem.

I had to fight the high rev with the brakes on the freeway entrance stop light. I got on the freeway and exited by the dealer and stopped in for emergency service.