I have a 95 F-150 with a 5.8. I have noticed when idling, the engine will rev up aprox. 200 rpms, then back down. I pressed the gas and held it steady at 2000 rpms. It did the same thing. It would rev up to 2200 rpm and back down to 2000. Has anyone else run into this? What did you do to remedy the situation?

Thanks

 

Well, without hazarding too much of a guess, I would think that either the idle valve (IAC valve) is not working , or very dirty, or you are suffering from some carbon buildup in the intake?..Dunno...like i said...guessing..

Maybe try to pull the computer codes to see if the computer is sensing a problem...Would start there and we can help you with codes if need be....

Ronnie

1987 F150 Reg Cab, 302MFI, AOD, 3.55 Rear, K&N Filter
https://www.ford-trucks.com/user_gallery/displaythumbnail.php?&photoid=4972&.jpg

 

>I have a 95 F-150 with a 5.8. I have noticed when idling,
>the engine will rev up aprox. 200 rpms, then back down. I
>pressed the gas and held it steady at 2000 rpms. It did the
>same thing. It would rev up to 2200 rpm and back down to
>2000. Has anyone else run into this? What did you do to
>remedy the situation?
>
>Thanks

check out the TPS (Throttle position sensor). It's been a while but i recall that was the problem i had on my mustang and it was the TPS.
hope that helps.

Rusty.