Looks like either the fuel pump SS relay, or the pump itself is goosed

Story - car wont start, and after some investigation, the fuel pump isnt running

(external fuel pump just after the fuel tank in the boot)

So, I jerry rigged 12 VDC with the pump in situ, and it ran

I then metered the feed from the fuel pump relay, at the pump, and had less than a volt when i turn the ignition

Aha, i thought, the relay is goosed

But, just to confirm, i tried to run the pump again with the direct 12 V, and it now doesnt run

SO- my thoughts - the relay was/is goosed, and my first attempt to run the pump with the battery primed the system?

I have also discovered that the relay shouldnt feed the pump with a constant 12v feed; its wired to the bottom of a coil and looks to be proportional to the number of revs...

Anyone confirm my theories so far, or offer better advice?

cheers

doesn't fuel pumps have a safety shut off pressure?

I'd be surprised if you are right about the RPM relating to the fuel pump power.

Isn't that side of the coil always live (with the ignition on), and the other side switched. That would be more normal.


Is the pump making any noise?
I assume you have fuel in the tank.

Matt

Yep, tank fuel of fuel, and the pump isnt making a noise

cabling to one side of the relay is from the ECU, the other is from the bottom of one of the coils....

Yep, tank fuel of fuel, and the pump isnt making a noise

cabling to one side of the relay is from the ECU, the other is from the bottom of one of the coils....

did you find a solution?