vehicle is 1994 xjs 2+2 4.0 engine. The car abruptly quit running and an obvious no fuel problem. Fuel pump fuse is good and bought a new fuel pump relay. I have power on one spade of the fuel pump relay plug, but the power goes no further than that. Double checked and reset the inercia switch and put new relay in the ems control in the passenger side footwell A post. Removed the fuel pump and the fuel pump motor works when direct power is applied. So I think there is something not allowing the fuel pump relay plug to engage. What can I check next.
Miami John

 

Have you checked the Heated O2 sensor fuse in the boot.
My 94 V12 had the problem and took six months to find the solution.
On my V12 coupe he fuse was in the boot on the right side.

 

John,

I wouldn't change any more parts yet as you're not really verifying where the original problem lies.

I would just follow through the wiring diagram in the logical order of Ign switch to Main Relay to ECU to Fuel Pump Relay to Pump to determine which one is preventing the pump from running.

When you say you "reset" the inertia switch, do you mean that it had tripped? Naturally, you could just bypass that if it shows to be faulty.

Good luck

Paul

 

Thanks Guys,
I will check the o2 sensor fuse and no the inercia switch did not trip, but I did the reset procedure anway
Miami John

 

Also when I first. turn the ignition key to on position, I do not hear the brief hum of the fuel pump. That is why I think it is something before the fuel pump relay connection causing the problem.
Miami John

 

Update: problem resolved! The cause of the no fuel was a bad fuel pump relay. I had bench tested the original relay, which clicked open and closed just fine, but the resistance was questionable. I did not know what the resistance should be, but I never got a consistant reading. So I installed the new relay cleaned all connectors and it fired up So even though a relay may click open and closed, testing it further is advised.
Miami John