No injector pulse on one injector..need to find cause

[oomchu]

Hello,

I have a '98 ZX2. Recently, my car started misfiring. I'm not sure of the cylinder number, but it's the one closest to the driver's side. Long story short, I found that the fuel injector is not firing, if that is the correct term. I used some trick I learned on youtube which involves using a screwdriver to listen for the fuel injector clicking. Anyway, I made a noid light out of an LED and a couple of resistors and found out that there is no injector pulse. I know the noid light works because I tested it on the other cylinders and it flashes. Anyway, I'm not sure where to go from here. I've read elsewhere it could be the PCM but if that were the case it would probably affect every cylinder and if it was a crankshaft position sensor the car wouldn't start.

Thanks for any help.

[oomchu]

Hello again,

I have determined that I need a new PCM. The only thing left to do was check to see if the wire from the PCM to the number 4 fuel injector had a resistance less than 5 ohms and it did. Does anyone know where I can look up OEM part numbers for a 1998 Ford Escort and the what I need to do to swap a PCM from one car to another?

[DeltaP]

Have you tried swapping injectors from another cylinder to see if the problem travels with the injector?
As for part # go to any Ford dealer website,( like: www.oemfordpart.com for example), type in yer info and you should have it.
An also see: www.youtube.com/watch?v=vTKNdV1Zn7Y for additional help and tips. HTH

[danielsatur]

If the fuel injector signal is lost, it could be a bad connector or a fatigue/ broken signal wire from the PCM to the injector.

[12Ounce]

I agree ... very likely to be a harness issue.

[hakachukai]

Check it at the ECM. You can insert multimeter probes into the back side of the socket where it plugs into the ECM.

If you find 4 good injector signals, then you know for sure that the problem is in the wiring harness.

If you find 3 good injector signals and one lost signal then:

#1. Switch the non-function injector with a known good one. It's possible that something could be electrically wrong with the injector that is actually killing the signal being sent.

#2. If that makes no difference, check and clean the connector socket to the ECM. It could just be a bad socket connection

#3. If all that fails, it's probably a bad ECM. Either replace it, or if you feel adventurous you can open it up and look for bad solder connections in the ECM ( since you have nothing to loose at this point ).