Cranks, no start, has spark, has fuel pressure at fuel rail.

[Canada]

This Grand Prix has given me a bit of trouble in recent weeks........orginally, the car would run until it reached operating temp, then die....no spark. Turns out the crank sensor had a minor crack in it and from the expansion due to heat was enough to cause the signal to die...killing the car. Replaced the sensor (had to remove pan to remove sensor....that was fun)....car started fine....ran for 20 min or so....ran great. Shut it off, cleaned up......tried starting again... no go.

I have spark....I checked the front three cylinders (which checks all three coil packs)....just fine. I have fuel pressure at the fuel rail....I pressed the test port with a screw driver....all kinds. This proves the crank sensor, ignition module, coil packs, wiring, pcm, fuel pump, and fuel filter are ok....at least I think so....would you agree?

I removed a plug.....wet as hell...in fact, the three front plugs are all wet. I let them dry out.....still no firing happening....I still have spark and fuel pressure though.............what IS the proper spec and testing procedure?

I ohm tested the injectors........mind you, I have no idea what the proper spec is.....but I measured them at 4 ohm, 14 ohm, and 13 ohm.......this is with a cheasy Craftsman voltmeter.....not a fluke, but should be good enough.

So it seems as if I am getting to much fuel to the cylinders..........this could be cause by bad injectors, bad harness, bad pcm, or a bad fuel pressure regulator......at least in my train of thought.

Any ideas?

[quantum110]

The injectors should be between 11.9-12.5 (i think thats the upper number, maybe it's a bit more) ohms. I don't think your suppose to have more than .4-.5 ohms of split between any injector either.

[Canada]

So the car started this morning and drove fine.........parked it and restarted fine 3-4 times.....about 15 min later went back out to restart again...same thing...plugs wetter than hell.

So something is causing the injectors to be turned on while the motor is off.....granted, there pry are a few bad injectors, but thats not the main cause of this problem I don't think. I'll pry swap in my spare ECM and check the injector harness for any shorts to ground.

[LQ1]

sounds like your on the right track, possibly the FPR

[Lyle's GTP]

I think your injectors are leaking. That causes the engine to be flooded. When you left it sit the fuel evapoorated from the cylinders. When you released the fuel pressure it stopped the leak. I'll bet any money that if the car is left for a couple minutes, it will be fine. Any longer, you're fucked. Get new injectors, or send them into witch hunter for servicing.

Lyle

[Canada]

Yep.....thats what we are thinking as well.......I swapped the orginal PCM back into the car and the same thing has happened.....we are currently waiting for the fuel in the cylinders to dry off.

Between the miles (134k) and my experience with these injectors.....they are bad.....I'm NOT sure if all of them are bad or not. Would one bad injector on one bank cause all three to to allow more fuel past ( BTW....the car is MPFI)? Or is it a matter of a seal or some such inside the injectors that are bad. (Mind you, I'm not real positive of the internals of an injector.)

I don't think a bad FPR would cause this to happen........the pump doesn't make enough pressure to cause fuel to blow by the injector.......at least in my little realm of thought.

BTW....can you give more info about witch hunter? I assume they do some sort of performance rebuild on injectors.

[Canada]

I found the link via the main page......sounds like a pretty decent setup he/she/they has.............and from reading his page, its sounds like the pintle and seat aren't sealing from there being a lack of fuel in the injector which allowed for the deposits and seals to dry out.

Plus, at $12 an injector, even if he can save half of the injectors....that beats paying $60 each from O'Reilys or AutoZone (GM List is $130...$60 or so via GMPD).

I should also add I emailed the guy and he agrees that something is blocking the injectors from fully seating.....causing the fuel to leak past. My question to you guys, is how well does the injector flushes work with something this dirty?

For instance, the type we have at work is what Wynn's has......they give you a bottle to flush through the injectors (uses a rig that uses shop air to blow the stuff through the test port on the fuel rail while the fuel pump relay is pulled and the regulator is disconnected), a spray can to clean the intake manifold, and a can to dump in the take.