95 F150 needs help please

[mayerst]

Gentlemen,
I have a somewhat unusual problem. I have a 95 F-150, 5.0 Lt., auto trans. When starting the motor the check engine light flashes 4 times and the idle speeds up momentarily, it will then drop and sometimes nearly stall. The idle is erratic for 30 seconds or so and smooths out and runs fine. This happens at cold start mostly but has happened when warm as well. This past weekend I replaced the throttle body with Ford parts for an unrelated problem. The new throttle body came with a new IAC and TPS, again both new Ford parts. Cleaned EGR replaced PVC. This has made no change. I am unable to retrieve any codes other that the “system pass “ code. Other than this the engine is running fine, no burning oil, no change in fuel mileage, has good pickup, and no apparent vacuum leaks. I am writing to you today to see if you have any suggestions as to what I may be overlooking or if any of you have had similar experiences. I would like to thank you in advance for any help you may be able to provide.

Tom

[way2old]

Look closely at the EEC IV connection. If there is corrosion or two wires shorted it may cause this. Sounds to me like it is going into engine running self test. The 4 flashes indicate an 8 cylinder and the revving and stumbling is when it is testing the EGR. I jumped the connection one time and forgot to take the wire out and the same thing happened. Happy hunting.

[mayerst]

Originally Posted by way2old

Look closely at the EEC IV connection. If there is corrosion or two wires shorted it may cause this. Sounds to me like it is going into engine running self test. The 4 flashes indicate an 8 cylinder and the revving and stumbling is when it is testing the EGR. I jumped the connection one time and forgot to take the wire out and the same thing happened. Happy hunting.

Thanks, I never thought of that. I'll let you know how it turns out. Thanks again.

[stang805]

there is a tsb about problem with cold starts because of the injectors in them, i dont know if it would cause that kind of problem or not. it could be self testing, you may just need to reset the ecu