96 Lumina 3.1 NO FUEL PRESSURE AT ALL HELP, please!!

[chubbygoatboy]

I am working on a 96 Lumina with the 3.1 .. It has spark, if you give it a little shot of ether, it fires. But, with pressure gauge on the fuel rail, no pressure... I checked the relay, and the associated fuse, they are OK. I pulled off the connector near the tank, the 4 pin one. Checked and I had 12v on one pin, I assumed this was the power for the pump, so then assumed bad fuel pump. I replaced it, the strainer and the filter. Still NO FUEL AT ALL.. I also checked the old pump with a battery direct connection, and it works fine. The pump DOES NOT RUN either. What else could it be?? I need to get this back on the road again quickly. Any thoughts are greatly APPRECIATED!!

[maxwedge]

Gray wire should be 12v, black wire is ground at connector, confirm 12v and ground at these wires, of course when key is turned on 12v will only occur for 3 seconds, but gd should be constant. also check this link if necessary. http://autozone.com/servlet/UiBroker...3d800eda79.jsp

[chubbygoatboy]

Thanks! I will check it out in the morning. If I do not have voltage at the gray wire, what should I look for next? Any ideas? Thanks

[maxwedge]

Check that diagram. PCM powers up the relay look at those circuits.

[chubbygoatboy]

Maxwedge, here is where I am at now. I checked at the tank connector as you mentioned, and the gray wire has no voltage, and the black is a good solid ground. So I direct wired the new pump that I put in with 12v and it works fine. I get about 44 psi on the rail. So I tried to start it with the direct battery hook up on the pump, and it still will not start, and the rail pressure stays at 44 psi, with the direct pump hookup off, even still at 40 psi after several minutes. So I am assuming that whatever tells the injectors to open, and turns on the pump, is not working. What is that mechanism?? If I spray ether in the intake, it wants to fire, and I had checked spark and it is fine. I also hear the relay click when the key is turned on, I even tried the AC relay swap. I also tried to pull the codes and my reader says "FAILS TO LINK". I am leaning towards the computer. Could that be it? Or what else could it be???? Is there a theft deterent or a fuel shutoff somewhere like Fords have?? THANKS

[maxwedge]

The injectors are not pulsing, there are fuses in these circuits check all the pcm and injector fuses. Does this have the vats chip key?

[chubbygoatboy]

I have checked all the fuses, I think. The key does have the little pc. sticking out of the key. One other bit of history, the car has been getting harder and harder to start, until it crapped out completely.

[richtazz]

Since you're not getting injector pulse with the fuel pump hot-wired and adequate pressure present, and it fires with ether (this all but eliminates the crank position sensor and ignition module), I'd put my money on a bad ECM. Double check the ECM fuse, but I doubt it's that simple.

[chubbygoatboy]

Is the ECM and the ignition module, the same thing? Is it the part under the coil packs? Or the main computer? THANKS

[maxwedge]

Ign module is under the coil pack.

[richtazz]

As max mentioned, it could also be a vats issue, as a bad key signal/vats problem will kill power to the fuel pump. But again, since it won't run with the pump hot wired, I'd still lean toward the ECM (main computer). Max, do you know if the VATS also kills injector pulse via the ECM, or just fuel pump power?

[maxwedge]

Rich, it disables the starter and fuel pump, not injector pulse as far as I know.

[chubbygoatboy]

Well, it's getting worse. I had one of my coworkers come over tonight with his fancy shmansy reader and it shows nothing. Like the computer is not even there. We checked and the computer is getting power on the wires it supposed to, we have checked everything we could think of, (and he is a diagnostics wizzard), and can't quite figure it out. I will keep posted what we find. thanks for all of your inputs! If you can think of anything else, let me know!!

[maxwedge]

Nothing meaning no power to the scanner, remember the liter fuse is what powers the obd 11 scanner.

[chubbygoatboy]

Maxwedge, what is the liter fuse? The "nothing" I was referring to is a failure to link message on the scan tool.