Ok guys here is the problem...

I have an 08 f150 with a 5.4. It has 21,500 miles on it. It has run great since I purhcased it brand new. Until recently. About a month ago, when I got home from work, i put it in reverse to back into my parking spot, and when I put it in park, the rpm went up to about 2500. I turned the truck off and started it back up and everything seemed fine. Over the course of the next couple weeks, it happened a total of three times and eventually started to do it when in drive at stoplights causing the truck to surge forward. I took it to the dealer and was able to get the problem to surface while on a test drive with the service advisor. Well after two trips to the dealer, and a total of 3 1/2 weeks in the shop, i got the truck back after they replaced the throttle body. Driving it a bit ago and it did it again. No codes are shown and no warning lights have ever come on. Has anyone else had any similar problems, and if so what was done to fix it? Any help is greatly appreciated.

 

Did they just replace the TB and not the Throttle Position Sensor on the side of the TB? I would hope they did, because it sounds like it might be sending some bad signals to the PCM.

I had this problem in my '01 Expy with the 5.4L Triton, although not as bad as yours seems to be. Mine never revved up to 2500rpm, it would just surge forward sometimes when coming to a stop. Never figured it out what was causing it.

 

iv had this problem with my truck mine did the same but it sometimes stalled coming to a stop. i got it scanned and 6 battery codes showed up. they cleared them and i got a new battary and it runs fine. they said low fuel could cause this too