Hi Steven, more issues remember when I said I was a happy man, well I'm here to say that was premature a couple of days later I tried it and I heard nothin, no pump what happened now? Crap, I left it alone, a day later I went back in the garage and tried once more and again I heard the pump running mmmmm! so I hooked up what I wanted to and tried it again, nothing again and again nothing, so my question to u is what is going on, is the pump sensing something that isn't there or do I need a computer? Regards. Errol
This thread is not a good place to put your question about a no start condition on your L-body. May I suggest that you start a new thread in the help forum and give the needed information on what you have, what you have done, and anything that might help. Describe the diagnostics you have gone through, what you have tested, etc. I'm sure that the gremlin will be found.
It's a good idea to use the no start diagnostics available on this site to determine what is missing, then work the problem that you identify. One trick that I have used is to place an LED on a length of wire. Then I put one LED on the (+) coil wire and to ground, one LED on the connector at the fuel pump, and one on the power wire to the fuel injectors. The LEDs by the way have a (+) and (-) side so you have to connect them properly to get the light.
When properly connected, all three LEDs will illuminate when you first turn the key...for about 1 second. That is the ASD relay turning on to prime the system, then shutting off. This is controled by the LM. The LM they will shut off the ASD by removing the ground till the HEP signals the LM during cranking. If the LM sees a HEP signal, it will turn the ASD circuit ground back on and the LEDs will light again during cranking and the car should start. If one or more or all the LEDs do not light then you will know which of the three (or all) is the circuit with the problem. If they all go dark during cranking that typically means that the LM is not seeing a HEP signal and it should store a fault code for that. That could be a faulty HEP or bad wiring or a loss of ground control.
If you can ground the diagnostics connector and hear the pump run, then that is typically a sign the ASD relay is able to function but not being grounded by the LM(which can be bad wiring), or the LM could be faulty. If you isolate the pin in the LM that controls the ASD relay, you can try a test by grounding that pin and if the pump then runs when the key is turned to ON, the LM is likely bad. Just remember that the LM has to get a HEP signal and after two key ONs it will not run the ASD till it sees a HEP signal.
The ASD control pin is #17 on the red connector. It should be a Dark Blue/Yellow wire, it's circuit K19. If you ground that PIN and the pump runs like it should when you turn the key to on then that means either that pin has a poor connection at the LM connector or the LM is not grounding the circuit as it should. It will not ground the pin unless it sees a HEP signal remember that and it will only ground it for 1 second the first 2 times you turn the key till it sees the engine is cranking and a HEP signal is coming in. But if you ground pin #17, you are by-passing the LM circuit entirely and the ASD relay should close and the pump should run, you should also have power at the coil as well as at the injector harness for the injectors.