92 ford thunderbird random cel



hi everyone and thanks for the help in advance, i have a 92 ford thunderbird 3.8l v6 lx naturally aspirated. 88,000 miles. the car has gotten gradually worse over time and no one can figure it out. the car has a hesitation (stumble) at idle no steady cel light on. when i take off from a stop car acts like its not getting gas for a few seconds then starts to speed up but the cel light pops on for a few secs then turns itself off but it randomly turns on and off (not flashing) at any speed or rpms constantly. sometimes it will come on and stay on till i bring the car to a full stop. i pulled codes and im getting engine lean on both sides bank 1 left and right, car never shuts off at all, ive replaced the following-spark plugs, wires, dizzy cap, iac, maf, throttle body gasket, checked all hoses for leaks, new gas cap. any ideas i am down to o2 sensors EGR components and the computer (hope its not that). please all help is great


What are the code numbers you pulled?



Try cleaning the throttle body and plate because there might be carbon deposits there.


Overly lean is caused by either too much air getting into the engine, or not enough gasoline. Presuming you’ve already ruled out the too much air theory (which can be quite an involved task), the cause must be not enough gas. The computer assumes a certain amount of gas is injected for each msec of injector pulse time. If that much gas doesn’t actually come out, it will cause this problem. Time to check for low fuel pressure or clogged injectors.

A clue can sometimes be obtained if there’s a difference in performance or symptoms when the engine is cold vs warm. Is there?

Misfires, O2 sensor , EGR, and PCV system problems are also possibilities, but less likely.


I’d suggest the strangeness of your problems and the age of the car may, indeed, suggest that the computer is at fault. Electronics have capacitors and capacitors age out. Since your ECU is now 26 years old, that may be your problem. Not sure what the availability of remanufactured ECU’s are, but any “new-old-stock” ECU’s will have the exact same problem due to the age of the caps. Sorry