How do I check the fuel pump for power, the relay is getting 12v the repair manual I have leaves a lot to desired. I know the pump is in the fuel tank, but where can I check power at pump and what is the wire colors and where is the inertia switch to check and are there any fuses to fuel system. The car just shut down, turns over good but I don't have fuel coming out of fuel line at fuel filter. I was trying to restore starting with engine first. Thank You

 

Hi garvan61,

Since Jaguar systems vary significantly depending on the year, model and engine, it is helpful if you edit your signature to include these details. To do so, go to your User Control Panel (User CP) and find the Edit Signature option in the menu on the left.

I just visited your profile and learned that your car is a 1991 XJ6. You can download the wiring diagrams here:

Jaguar XJ40 Electrical Guide 1991

You can download a mostly-complete U.K. edition of the Haynes Repair Manual here:

Haynes Repair Manual Jaguar XJ40

With the key in position II (ON), there should be 12 volts on terminal 30 of the fuel pump relay socket. If you bend a large paperclip into a U and use it to jump terminal 30 and terminal 87, the fuel pump should run. If it doesn't, either there is a problem with the wiring between the relay and the pump, or the pump motor has failed. If the pump runs, then the problem may be on the control side of the circuit. With the key in position II, the fuel pump relay socket should have 12 volts on terminal 86. This power comes from the Main Relay. To run the pump, the Engine Control Module grounds pin 85.

The inertia switch is in the forward left corner of the driver's footwell behind the carpet. The switch is a small black plastic box with a plunger button on top. If the switch is triggered, the plunger pops up. To reset the switch, simply depress the plunger until it latches in the down position.

Please keep us informed.

Cheers,

Don

 

I have discovered where to check the fuel pump, I am getting power to pump so I assume fuel pump is bad.

 

Are you checking at the electrical connector on top of the fuel tank while cranking the engine or jumping the fuel pump relay socket? When the key is turned to position II (ON), the ECM will only power the pump for a few seconds to prime the fuel rail. It will not apply power to the fuel pump again until it detects the engine cranking (via the Crankshaft Position Sensor).

Cheers,

Don

 

Still a mystery car!!!!!!!!!!

 

Thank You for your reply, I have power to fuel pump on top of tank , however the volts drop to around 10 volts I have not checked while trying to start will do. The tank looks easier to remove than I thought. Thank You

 

Thank You will check when I get a chance.