I have a 92 Bonneville, non super charged, automatic, a/c, power accessories, and I can not get it to run. It has been sitting for a while, and the battery was dead, so I swapped out the battery for a brand new one, and the car turns over, but it won't run, unless primed. If I prime it, it will run until the primed fuel is used up. I bought a fuel pressure tester and checked the pressure. With the key on, it has no pressure at all, if I attempt to start the car, the fuel pressure comes up to around 50 on the gauge after a few rotations of the engine. Anyone have any ideas on what to start checking, and where some things are such as the fuel pump relay, and the fuel filter? Thanks guys.

Fuel Pressure Regulator.

I looked at the regulator, and it is not leaking, and will hold vacuum pressure. Do you still think that it is bad ? Is there any way to actually check the fuel pressure regulator?

Fuel pressure should hold when you shut down, but even if it leaks down, it should come up to around 45-50 psi by turning the key on. I suspect the fuel pump.

Also, I was just looking everything over and attempting to use my scan tool on it, and I turned the ignition on and found that the oil pressure gauge was acting very erratic. I couldn't get the scan tool to work, but I am now wondering if the oil pressure activity and the no starting are related. The guage will zero out when you turn the key on, and eventually it will peg out at over 100psi. If I try to start the car up, it will bounce around and eventually peg out. I am not too familiar with electrical systems, but could this maybe be some sort of ground fault? Where would I find the wires that are used for the ground in various locations?

Again, sounds like the FPR failure I had. It was not maintining pressure when the car was off. To test this, let the car sit over night, the see if any gas comes out of the Valve Stem looking thingy on the fuel rail. Use all appropriate safety measures when doing this, If anything comes out, it'* gas, and your FPR should be fine.

But, I gotta go with the pump thing. But, iut shouyldn't matter if the car is running or not. As soon as it gets power (i.e., the key is turned on) it should at least build up power, whether you crank the engine or not.

The pressure holds when I shut the car down, but ony for a few seconds, then it starts to gradually drop until it hits a 0 reading. When I turn the key on, I don't get any pressure, unless I try to start the car. I ran 12 volts to the the fuel pump relay bypass and I get the same reading around 50, but the same thing happens when I disconnect the constant 12 volts, it gradually drops to zero. With the pump running up to proper pressure, I figured it would start, but it continues to run as though it is not getting any fuel, and will only run when primed by spraying starting fluid into the throttle body. Also, I probed the wire terminals of the fuel injectors, while plugged into the injector, with a test light and found that both terminals showed voltage. Should I be getting voltage at both wires on the fuel injector with the key in the on position? Funny thing is that I tried to start the car with the test light "lit" from the voltage of the fuel injector terminals and the car acted like it wanted to start .

The FPR is way cheaper and easier to change than the pump. Plus, I think the FPR is allowing all that fuel back out the return line. In my car, My pump made 80psi on the bench, but only 35psi in the car. The car requires 50ish psi to run right. I think maybe as the pump comes up, the FPR funtions properly until 50+psi are acheived by the pump, Therefore blowing by the FPR.

I agree....try a new fpr....it easiest and cheapest........

The more I think about this, the more confusing it gets. Key on, no fuel pressure (there should be). The pump should run for about 2-3 seconds and if the engine is not started, it shuts down til it is cranked. That means the pump is not getting voltage. Fuel pump relay? When you begin to crank it comes up to specs. but will not start. That'* the part that is very confusing. Find the fuel return line and clamp it off with vise grips or pliers while a friend starts the car. If it starts, replace the FPR. If it doesn't ........ shoot it!