I'd say 31psi is a tad too low for the injectors to fire off.

I do love Rock Auto for parts, but I'll have to check out Parts Geek next time I need something.

Currently replacing the Denso pump right now. Dropped the tank and took apart the old pump assembly and reinstalled the new one with the new hardware ... taking a break at the moment

Mike, I'm not sure that was the exact fuel pressure. I really should have written it down at the time. I'll definitely check it when I get it running again, for curiosity'* sake and peace of mind.

So we completely replaced the fuel pump ... tank'* back in, every hose is hooked up and clamped and back together with all of these beautiful and shiny new parts. Turned the ignition ... and nothing.

Hindsight is 20/20 and I should have done electrical tests on the fuel pump system yesterday when it wouldn't start, but I was so convinced that the pump had given out.

Does anyone have information (or tips for getting information) about the relays on the firewall under the hood and which relay is the fuel pump, and/or about the circuit diagram for the fuel pump system? All I have is a Haynes manual and the relay section is just general information and the circuit diagrams say nothing about the fuel pump.

Thanks is advance,
Kelly

I believe your fuel pump relay is located behind the passenger side kick panel. It should be labeled on a white sticker.

Another thing you can look for and I'm not sure yours would have it, (the 95 bonnevilles did) is a single orange wire with a single terminal at the end of it near your battery. It'* not connected to anything. If its there, find a way to connect it to the POSITIVE side of the battery. This bypasses everything on the car straight to the fuel pump.

Mike, thank you for the reply. We went around tonight checking voltages and trying to activate the fuel pump with a secondary battery to narrow down the trouble site in the fuel pump wiring. I forgot about this orange wire near the battery and didn't test that.

However, we were able to start the fuel pump at the connector nearest the fuel tank. Then it couldn't be started from the fuses, and we continued to narrow it down like that until we found a bundle of wires in the trunk immediately behind the back seats. We fiddled around with that, looking for a bad wire. One of them, a black ground wire, was disconnected from the chassis. However, it had rusted and looked like it had been disconnected for quite a while and therefore could not have been the cause of my no-start problem, which began three days ago.

We stripped the grey wire of the bundle (according to the Haynes repair manual circuit diagram, this was the fuel pump wire) and tested it to see if it was getting any volts when we turned on the ignition ... WELL ... we heard the fuel pump start up and pressurize the system!!! We were able to start the car at this point!

It seems that something in this bundle of wires was not quite making good contact somewhere, and our fiddling around with it completed the circuit. We gorilla taped down the bundle of wires to the body of the car underneath the carpet of the trunk instead of having them float around ***** nilly, and the loose ground wire was repaired. Car still started after this.

I will update if I still have the starting problem (the thing that happens 20-45 min after parking, which I began this thread with), but for now ... a beer

I was able to start the car without repairing the black ground wire, which is why I am sure it wasn't the cause of the no-start problem.

Wow, you do have a weird electrical gremlin in your car.

Hello!

I wanted to update this thread -- The starting problem is gone. It must have been the fuel pump this whole time. I tested it out a couple times the first few days after getting it running again and didn't see the problem, but I didn't want to speak too soon! (I actually still have reservations about posting this, haha)

However, like you said Mike, now I have an electrical gremlin to chase around. Good thing is, the symptoms for that aren't too bad. More details in a new thread here.

Thanks for your help everyone. It'* wonderful to have a support team for these aging cars.