#7 injector no pulse

[Malice]

first off, I'd like to apologize for constantly whoring up the tech sections with awful tech Q's. I'm a bad mechanic, and my car is in horrible shape. It's not a good combo.

I got my engine back together, and my #7 cylinder isn't firing. WHen I spray water on my header primaries, the water instantly evaporates from all of them but #7.

First, checked the spark wire's resistance. It was 11.03K ohms.

Next, I pulled the spark plug out and ran the engine. I visually watched the spark plug fire, and..... I sniffed the air being compressed out of the open spark plug hole. It had no fuel odor at all.

Next, I pulled the injector harness off of #7 and hooked a multimeter to it. With the engine running, it was showing me a constant 12.8ish volts. My multimeter couldn't keep up with the rapid injector pulse signal, so it was just showing a constant voltage.

Finally, I put everything back together, and physically touched the injectors. I could feel the good injectors clicking. I couldn't really tell if the bad one was clicking or not though. If it was, it was weak.

Any ideas or additional diagnostics before I pull of my fuel rail?

CLIFF NOTES: #7 injector won't pulse even though it has an elec signal. WTF?

[krayzie7th]

bad injector maybe?

[Chris]

http://shbox.com/1/1995_pcm3.jpg



How are you testing the electrical. If you are just testing for power you will always have it . The pcm pulses the ground of it .


With the test you have done I would say swap it with a different injector and take a looksie

[Malice]

Werd.

I'll try swapping out injectors and see what happens.

[MEAN LT1]

Throwing a shot in the air. Maybee you have a bad injector driver and not firing off that injector?. But knowing that you should have thrown a code for it. Sorry if this wasnt helpful.

[Malice]

Throwing a shot in the air. Maybee you have a bad injector driver and not firing off that injector?. But knowing that you should have thrown a code for it. Sorry if this wasnt helpful.

I scanned the codes, but that didn't come up. My code reader is a total piece of crap though. It always shows me the same two codes, no matter what is wrong with the car.

I'll look into it more though.

[Chris]

If you want to try and break the injector free pinch the return line for a few seconds that will dead head the pump and the pressure in the system will double. Just only do it once or twice because it puts alot of stress on the pump. That is what we normally do during a fuel injector cleaning to make sure they get off the soot kicked out of them.