This is a puzzler. My # 4 fuel injector is not working. I replaced the injector and it did nothing. The lead to the injector has 12.6 volts and the one I removed will funtion when I attach it to the other leads (1, 2, 3). When I try to pull codes from the ECU, the Check Engine Light just stays lit.

Please help before I rip my hair out.

Thanks

 

What makes you think it's the injector? Because the cylider isn't firing? Could also be the spark plug or plug wire. Have you checked for spark?

 

That was the first thing I checked. Spark is fine. The other three injectors are clicking when I listen with a screw driver. I am at a loss.

 

Possibly damage to the ECU's injector driver circuit? Broken connector or harness trouble?

 

Check for continuity from the ground side pin on the injector plug to the number 4 injector pin on the ECU. If there is a break in the wire then the ECU cannot trigger pulse to that injector. Make sure you completely unplug the ECU last thing you want is to brick your ECU by accidently shorting a neighboring pin.

If you have continuity then its a ECU problem, if you don't then its a break in the harness somewhere. Either trace the brake or run a new wire.

Hope this helps

 

Also what do you mean when you say the "lead" to the injector has 12.5v? Do you mean that you have 12.5vs across the injector 4 + and - pins or that you have 12.5v between the + pin and a chassis ground?

Its important because if you have 12.5v across the injector pins constantly then you have a short to ground on that injector.

 

This is a 17 year old thread.

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