The main fuel pump on my 1989 740 GL will not run. The car was running fine until yesterday, when I shut it off for about 5 minutes to drop off some packages at the Post Office. When I tried to restart it, I got nothing but the starter motor trying its best to turn the engine over.

Having owned many older 240 models in the past, I knew the fuel pump relay can be troublesome and therefore keep a spare in my glovebox, but it was of no use. I even jumpered the 30 and 87/2 pins in the relay board and the pump still will not run. So I replaced the pump with a working spare I had and still nothing.
Does anyone know if the car's computer plays any role in controlling main fuel pump operation? It won't even activate when my key has been turned to the number II position on the ignition switch, allowing the pump to turn on for a few seconds and go into its little self-priming mode.

Any help with this problem will be greatly appreciated and thanks in advance!!!