My 88 Bonneville (3800 V6, 140K miles) cranks but will not fire. It has spark. Fuel Injection Relay fuse ok. No fuel to injector rail. I don't have a pressure tester, but there is no gas if I press in the valve on the fuel rail. After reading some posts, I put 12 volts to the green primer jumper and did get fuel to the rail. It then fired but wouldn't start.

Can I assume the Fuel Injection Relay is OK since it pumps gas via the green prime jumper? What else could be stopping the fuel pump at startup? Car was running OK when parked for the night. Next morning no start. The only unusual thing was for the last few weeks the car would sometimes die after first startup if you immedially put it in reverse. If you restarted it and let it idle for 30 seconds no problem. Not sure it that is related. Bought the car 5 years ago with 73K miles. Has always ran good. Would appreciate any ideas. Thanks.

No whrring sound when you turn on key. I even disconnected the gas lines going to the fuel rail and watched for gas to pump while my son first turned on the ignition and then cranked it over for a few seconds. Nothing. The only way to get gas is to energize the green prime connector by the battery.

The 6/12/04 thread #19934 titled "My car cut off on me this morning" has a post from randman1 saying if the prime connector makes the fuel pump work then the relay is ok. If that is so, then something is stopping the ECM from sending 12 V to the relay. Besides a bad ECM could the crank sensor do this? I will try to test for 12 V at the relay and Fuel injector fuse under the dash on the passenger side when the ignition is turned on and when cranking. I assume I will have to drop the tank to test the connector on the tank?
Thanks.

That is incorrect, the prime lead goes direct to the pump. If connecting to the prime lead gets gas then try this - connect 12v to the prime lead for about 10 seconds then remove. Try to start. If it does and continues to run then the problem is the relay. If it does not continue to run then there are other wiring problems.

There are three paths for power to get to the fuel pump
1) prime lead
2) ECM turns relay on for 2 seconds when key is moved from off to run.
3) When oil pressure comes up enough to turn idiot light off, fuel pump gets power from oil pressure switch NOT through relay.

I now have No fuel pressure even when I use the prime lead. When I used it in the past, I got very low pressure. I'm going to change the fuel pump. I will let you know if this fixes it.

While you're down there, use a test light or multimeter to test the wires going to the fuel sending unit before and after the connector. Specificaily the gray and black/white wires. That was one of the first problems I encountered with my 90. The fuel pump was actually good but the ground wire was broken inside the factory connector. Yhis will only add a couple of minutes to your repair but will save hours if it'* just a connection.

Fuel pump was bad. Also replaced harness, sock, and inline filter. Old Red is back in business. Thanks for the input.