My check engine light came on so I did an error code check on my 94 GXE. I got a 51, which is a Fuel Injector Signal Cirsuit Fault. Does h
anyone have ANY idea what this means and maybe even how to fix it? The car runs pretty crappy, so something is definatly wrong. Rough Idle, and little power at low RPM's. Anyone had a 51 before? Thanks. *I Searched Already*

 

Don't know what code 51 mean, but the symptom you describe seem to indicate one or more injector has gone bad.

 

Yeah, 51 is the Injector Circuit. To check to see if an injector has gone bad, check the resistance between then two terminals in the injector harness connector of the 2, 4, and 6 cylinders. When you unplug it, you'll see two terminals in the connector.... the resistance between them should be 10 - 14 ohms. If it's not, then replace the injector. For the 1, 3, and 5 cylinders, disconnect the sub-harness connector for injectors. Check the resistance between the terminals to see which one has gone bad. The sub-harness connector looks as follows:

a b
c d

The piece of plastic that juts out is the top of the connector. Ok, to check to see if Cylinder #1 injector has gone bad, check the resistance between terminal b and d. Cylinder #3 is terminal b and c. Cylinder #5 is b and a. The resistance should be 10 - 14 ohms.

If any of the readings are way off... then replace that injector.

I've heard some guy up hear said something about getting a 2 foot long 1" diameter rubber tube... and then put it up to each one of the injectors to see if you hear an operating sound. I guess it works like a stethoscope. I hope this helps.

 

Okay, so I did a check on all the injectors with an Omh meter. All the injectors are within specs except my number 4 injector, which fails to give any Ohm reading at all. I tried starting the engine and then unplugging the injector cable to number 4, the engine ran the same as it does with it plugged in.

Is the only option now to replace the injector?
Should I just replace the troubled one? Or all?
Anyone have a $$$$ Amount for what they paid for this kinda work?

Thanks

 

The only other thing you should check is the continuity between the ECU and the harness connector. But, in order to do this, you will have to see a large illustration on which terminals to test. It's too complicated to describe in words alone.

Since, I've never had to replace an injector, I really don't know anything else. I am sure you would need to replace that injector only. But hopefully, others will chime in with more input. Later.