I have a 1990 F-150 302 V-8 5-Speed that has suddenly started idling at 2200 to 2300 RPM'S AND WILL NOT KICK DOWN. Vehicle was running fine. Left work and made one stop, next time I cranked up engine goes straight to 2200 and won't kick down. I have read the DTC codes with an Autoxray EZ6000 and when doing KOEO returns Code 11 - System pass current code and also Code 11 memory code. It is difficult to let the engine warm to Normal Operating Temp. when it sounds as though it is about to explode, but when running KOER scanner returns Code 12, obviously, RPM unable to reach upper test limit. The following are things I have checked:

1) TAB solenoid - reads 75.5 Ohms 2) TAD solenoid - reads 75.5 Ohms
3) EGR EVR solenoid - reads 43.5 Ohms
4) Disconnected accelerator and cruise linkage at throttle body
with no effect.
5) Replaced EGR valve about (3) months ago.
6) Replaced Idle Speed Control valve, also called IAC Control valve
Sunday 3/14/04 - no effect.
7) Removed air intake hoses from air filter housing and the
Throttle Body plates appear to be closed tight.
Things I have not checked:
1) Smog pump
2) Air Bypass Valve
3) Air Control Valve
Don't honestly know if any of this Emission Control stuff is the problem??
If anybody out there has experienced this problem please let me know. At this point about all that is left is the ECA or ECM which ever you prefer to call it. I need some HELP!!!!!

 

Saw another post here recently where a new TPS solved a problem like that. Have you tested that?

 

I'd begin to suspect either the TPS or a vacuum leak of some kind. I doubt that the emissions controls are causing these problems since they only affect exhaust. The computers rarely go bad, although it is possible. From the symptoms you describe, it doesn't sound like a bad computer.

 

i'd say TPS. common Ford thing.

easy to test part. i woulda started there first with bad idle.