Noid Light and Injector Testing

[95strokerPSU]

I just want to test my injectors and have three questions about noid lights.

1. Where and which one should I get?

2. Do disconnect the coil and test only during cranking?

3. Do you unplug the injector your testing?

Thanks
Dave

 

[blksn955.o]

1. just ask for a noid light, There is really only one style as far as I know.

2. it would be a good idea to un-do the coil wire to keep the car from starting up.

3. you have to un-do each inj. at its plug in point to the harness as the light fits into the plug end of the harness.

It would be best to have someone turn over the car while you look for the light. It would also be a good idea to do this in a dark area to see the light better.

 

[95cobraguy]

the noid light test doesn't actually test the injector, it tests the wiring to the injector. the noid light detects if the computer is sending a signal to that injector. if your car isn't misfiring i wouldn't even bother.

 

[95strokerPSU]

the noid light test doesn't actually test the injector, it tests the wiring to the injector. the noid light detects if the computer is sending a signal to that injector. if your car isn't misfiring i wouldn't even bother.

Yeah thats true, but when I had my car SCT tuned they found out that I was only running on 7 cyclinders (I knew there should have been more power) and that the computer had a short and wasn't pulsing the #3 injector. I should have had my injectors tested over the winter when I had everything apart, but next winter I'll either be getting head and intake work done and a custom cam, or nitrous...so I'll be stepping up to 30#s

I guess after my alternator issues and last night my fuel line coming off the rail, I just want to check everything I can to ensure my car is running 100% now that the nice weather is here and I'm gonna be driving as much as I can.

 

[95cobraguy]

well i guess the question is what are you going to do about that # 3 cylinder? either the injector driver in the computer went bad or there is a broken wire in the injector harness.

 

[95strokerPSU]

I'm an idiot...forgot to say they replaced the computer before they tuned it.

 

[HISSIN50]

Correct - the noid light checks for constant 12 volts to the injectors and that the puter is pulsing the ground pathways.

To test the injectors themselves (in the car), run a cylinder balance test. In Dave's situation, it would have found that cylinder to be non-contributing.

Good luck.

 

[Zero Signal]

Or just listen to them with an automotive stethoscope, works like a charm