01, 7.3l, 4wd. About 185k miles. When I put the truck in park it idles up high for a few seconds and then comes back down to where it should be. I have had the truck for three years and it just started doing it in the past week. (never done it before that) Any ideas what it could be? It this a hint of a problem to come? Thanks guys...

 

I just spend almost an hour searching the forums after I posted this and couldnt find any similar problems.... HELP!!!!

 

Haven't heard this one before.

Has it been unusually cold in Biloxi?

Does it do this when it is warmed up?

If you tap the brake does it idle down?

They are supposed to go to high idle but normally not until it is below the mid-thirties.

 

It does it when its warm and when its cold. I looked at it a little closer after posting... When you shift from drive to park it surges up to a little above 1k rpm's and then drops back down to normal. Its almost like what would happen if you bumped the accelerator pedal with your foot. It doesnt stay up long enough for me to be able to tell if hitting the brake does anything.

 

That happened to me to turned out to be my injectors and ipr why I donno but I also had a check engine light on to make sure you have oil

 

mine does this when i go from drive to reverse really fast or vice versa and if i put it into park fast.but mine only does it since i did the 10k mod not when it was stock.

 

Does it do the same thing when you shift from drive to neutral? You could have a trans range sensor going bad and the PCM doesn't know you've shifted to park. Does it still idle up in cold weather?

Could also be a sluggish/sticking IPR.

Jay

 

I just checked.... It does it when you shift from park or reverse INTO neutral or park

 

Any more ideas???

 

Like Jay said, while coasting (above 5mph, less then 25mph), does it do it when going from drive to neutral?

When I come to a stop sometimes, (fuel stations, etc) I take it out of drive while coasting. It always revvs up just a little bit, right around 1000-1100. Stock programming, tuned programming, etc. So that is normal for it to do that, but if yours is doing the same, from park or reverse, to neutral, etc, I think you could be looking at your range sensor like Jay said.

 

No reply has indicated that there is impending doom so let it be.

 

I know this is an old thread but I am having the same issue. I’ve already replaced the CPS with a motorcraft one, IPR, IDM, driver side injectors, fuel tank assembly. What could it be?

 

Ran into this issue on my 7.3 2000 ford f250. It was the tail shaft speed sensor. Which is either on the transmission or in the differential case on top. I bought a cheap one from dorman, and it did not work. Went to ford and bought the motor craft and so far its working. I'll try to post the part number later. Message me with any questions.

 

Thanks. I put A dorman one on the rear differential but it’s not working. May have to try a motorcraft

 

Good call on motorcraft for any sensor replacements.

Might be a longshot but check your battery connections. Fixed this guy's similar issue:

https://www.ford-trucks.com/forums/1...into-park.html