I have been searching the forums here and found some good advice. I found some threads that have the same issues that I am experiencing, but they are from almost 10 years ago and the replys stop before the problem was resolved. Anyway, here is a little breakdown of what I am experiencing and things I have tried, any other tips would be greatly appreciated...

1992 Ford F150 302 EFI, 178,000 miles. Sat and didn't run for 2 years. Brought it home and did the following
-replaced front gas tank
-replaced fuel filter
-changed spark plugs and wires and rotor
-new EGR
-new coil
-new fuel pressure regulator
-new pcv

Here is what I am experiencing.... Start the engine, drive and before it warms up, it runs fine. Shifts well, good power, feels smooth.

After it is warmed up, the engine seems to hesitate or miss while driving at a constant rpm, especially around 40mph and under 2000 rpm. If I step on the gas, it cuts out until it gets over 2500 rpm and then it seems to run smooth, until it down shifts and runs again at a constant rpm. If just feels doggy and like it isn't running on all cylinders. The check engine light comes on for a couple minutes but goes out (only occasionally).

A couple things I haven't tried yet.
-move PCV hose to top of upper intake
-check fuel pressure
-replace tps
-check vacuum pressure(I did try spraying starter fluid around vac lines to see if there was a leak)
-check exhaust back pressure
-replace fuel injectors

It is just getting a little frustrating. Runs great when cold, doesn't when warm. Seems like it is worse when under 2000 rpm, down shifts or as I am accelerating under low rpm.

Thanks for any advice.

 

I have been experiencing the exact same issues in my 1993 F150 351 Windsor. Error code reading indicated EGR as the culprit and I replaced it. No joy.
It has turned out to be the air idler control valve.

Good luck.

Larry in Key Largo

www.keysf150.com

 

Warm up the engine then run the Key On Engine Off (KOEO) tests and Continuous Memory display: Fuel Injection Technical Library » How To Run a Self-Test

That Check Engine Light (CEL) is trying to tell you something.

 

The codes were clear except KAM failure?

 

Thanks for the tip, I will add that to the list of things to try.