rpdjim1

Have a 1993 Ford F150 5.0 4x4 Standard Transmission.

Me: I know enough about working on trucks just to be dangerous. So I'm learning a lot as I go with this truck.

Have replaced the Idle air control valve and PCV Valve.

Persisting problem is that the engine high idles after it warms up. When shifting between gears specifically the engine will idle up to as high as 3100 RPM's. I thought it might have something to do with the clutch since the idle goes way up when shifting. But thats not the case because I can shift into neutral without using the clutch and it still will idle up to 3100 RPM's.

Any ideas on what might be causing this?

Thanks

speedysprocket

I had a similar issue recently and it turned out to be the TPS was bad. Any Check Engine light...?

rpdjim1

Yes. The check engine light comes on after the vehicle warms up. I have taken it to Autozone to see if they could check the code but the truck is so old they dont have the computer to check it. I'm replacing the TPS this weekend so hopefully thats it.

Thanks

VickMacky

Make sure to get a Motorcraft unit. I had issues with an aftermarket one.

qdeezie

Make sure this is a Motorcraft unit. Aftermarket PCV valves tend to cause idle and other engine performance issues.

qdeezie

The other thing is check for codes first. I once had a bad EGR position sensor causing a high idle and would've never known had I not checked for codes.