The perfect two cylinder ??????

[Coyote3]

I have a 1994 Explorer with a 4.0 and standard tranny. Have had problem with it only running on two cylinders. Have changed about every sensor known to man at it still fires on only two. Has spark at the coil pack and at plugs. Has about 120 psi in all six holes. Have almost come to the point of scrapping it but have to much invested in sensor on the darn thing. Have even tried a used EEC and ICM. Please help!!!!!!.........

 

[MrShorty]

I don't know if it matters, but it might spark someone's brain: Which four cylinders are dead and which two are good?

Are the injectors on the dead cylinders firing? gas getting into those cylinders?

 

[Coyote3]

Re:

Yes to all the questions that were directed. There is fuel to all injectors and fuel to all cylinders. The front two wires on the coil pack are the cylinders that are firing. Believe they are 1 and 6 dont know exactly without looking at the book? Have even tried the good old ether in the intake and does not make a difference. Plugs and wires have also been changed. Think its got to be an ignition problem but can't put my finger on it........

 

[MrShorty]

It sure does sound like an ignition problem, because it seems related to the coil. But you also indicated that all the spark plugs have spark, so that suggests that all three coils are working.

You said you tried a different ICM. Have you verified the wiring between the ICM and the coil pack? Just looking at the wiring diagram, if two of those circuits were broken between the ICm and the coil, that would cause what you are seeing.

 

[wood1]

So the engine ran fine, then all of a sudden it started to run on 2 cylinders?

What codes were set?