My 1976 530i failed to start in the garage after an uneventful outing a few days earlier. The engine turned but did not fire. I determined that no fuel was getting to the cold-start valve. When I looked at the fuel pump (under the fuel tank, I found a broken mount and the pump waggling under the car. The electrical wiring was pulled out of the car about an inch, along with the grommet. With the ignition switch on, there is voltage at the output of fuse #6. However, there is no voltage at the fuel pump plug. Some questions:
- Is it possible that the wiring to the fuel pump is separated somewhere inside the car? Is there a connector I should especially look for?
- When the ignition switch is on, should the fuel pump run, and can I hear it? It isn't now, of course.
- Is there a relay involved in running the fuel pump? The owner's manual is not clear. It lists (on page 127 in connection with emission control) a control unit, a cold-start relay, and a combined relay. How do I test or verify any of these?
- Is the diagnostic plug in the fuse panel of any use to me? If so, how do I use it? Thanks for any help. Fred (iflymach2)