A little background: The car has about 130,000 miles on it. A couple of weeks ago it started missing progressively worse over the span of a week or two until finally it would only crank but not fire. I decided to replace the opti since it's stock as far as I know (purchased at 65,000 miles and not replaced since).

Since replacing the opti with an AC Delco from the thepartsladi, I'm in the same spot with cranking but no fire. I've got spark coming from the coil and spark at the plugs. I did notice in the midst of troubleshooting that the ignition fuse inside the driver's door was blown. I replaced it and with continued cranking it hasn't blown again yet.

As for fuel, I get fuel spraying from the fuel rail if I press the schrader valve so I know it's at least somewhat pressurized. I haven't picked up a fuel pressure tester yet but will. Is there a certain pressure below which the injectors won't be enabled? The injectors have 12 V but I'm unsure if the PCM is sending pulses to the injectors. I'm going to try and pick up a noid light later today to check, but I don't think the injectors are being pulsed. After much cranking, I pulled a plug and it was dry.

I think that's everything I've checked so far. Anybody have any ideas.

Thanks,
Jeremy

 

I believe it's somewhere around 55-60lbs of fuel pressure that's required to fire the injectors correctly. Could be a good place to start, that's the next thing I would eliminate as a possible problem.

 

ya ounds like possibly a fuel issue

 

You only need 43-47 psi for the injectors to spray pretty sure spec is 44-47 psi

 

Give small shot of starting flued if it starts your issue is fuel! With vac off the FPR you should have 43.5 psi... Have you checked the ICM? You can listen to the injector with a long screw driver, or you can use a test light too....

 

I checked the fuel pressure today. With the key on, I get about 44 psi which quickly bleeds down a couple psi after the pump shuts off. It holds at about 44 psi while cranking. I haven't tried a test light yet for the injectors but I did check them with a meter. It doesn't look like they're pulsing because I get the same voltage between the hot injector lead and a known ground as I do between the hot injector lead and the pulsed lead from the PCM (both while cranking, about 9 V). So I guess the pulsed lead is a solid ground, not pulsing.

Is there anything that could cause this other than a bad PCM? Based on what I'm seeing with the meter, should the injectors be stuck open or does the pulsed ground cause them to close?

Thank you all for your help.

 

I hooked the car up to TTS Datamaster today. It doesn't show any DTCs but I'm not sure if they can be triggered just by cranking but not running. The injector duty cycle shows about 2% while cranking. Does this sound correct? Is it possible that Datamaster could show 2% duty cycle but the PCM not actually pulse the injectors? I'm not too sure where to go from here... Any ideas?

 

I finally picked up a noid light and the injectors are being pulsed. Is it possible to have spark with a bad ICM? Could the spark from the coil be so weak that the car wouldn't even start? I don't really know what else it could be other than the coil or ICM.

I appreciate the help.