Can someone please explain where I can locate the fuel pump relay on my 1988 M6?
On the fuse box cover it lists all the fuse no. and relays (K1,K2----K10) but I can not find any info on which one is the fuel pump relay.
My car won`t start, after running very well, when parked.
When I hook the fuel pump directly to the battery it runs, so fuel pump seems to be OK.
I believe it is the fuel pump relay that is the problem, but can not locate the fuel pump relay. PLEASE HELP ME #
under the dash, near the ECU. The ECU instructs the fuel pump to run. Without the correct inputs to the ECU, the fuel pump relay won't ever close. The fuel pump runs in cranking and in running only. ECU inputs include crank sensors and a 'start' signal that is derived from the starter motor via a skinny wire. This 'start signal' quite commonly fails and the result is a no-start as you describe. If the fuel pump is jumpered, there is (for a few minutes) usually enough residual pressure in the fuel rail to start the car (even with the fuel pump not running during cranking) and then the 'run' signal is used to trigger the fuel pump relay as per normal.
So a simple test is to see if you are generating a viable start signal (it also appears at the diagnostic port) and that the signal is getting the ECU.
