Fuel Pump Not Running

Hi Mike:

Thanks for your time on this one…all of the left side fuses tested good, once i restored power to the right side fuse panel and all the fuses tested good. I still have no power to the white and violet/purple relay plugs under the hood whether the switch is on or off.

And yes, there is the lightning bolt sign on the panel when I turn the switch on. didn’t know for sure if it was an actual fault or they were just lighting up while cranking. The transmission fault is also on in the panel. According to the manual the violet/purple relay is for the transmission.

correction:

the left side fuse panel was always working and it had nothing to do with the restoration of power to the right side fuse panel. The only fuses that I have found not to be working at this point are the two can relays under the hood as previously mentioned as there is no power at the relay socket.

Also all of the fuses in the center console are working…power is sent to the center fuse panel once the ignition is turned on.

Update:

I wanted to update the board on my progress or lack thereof on my fuel pump issues. Just to recap I have two 94 XJ40s. Both have the exact same fuel pump issue (fuel pump not running). I have a black one and a green one. The green one I just purchased as a parts car. The PO sad it developed a crank but no start and after a year of trying to start it he gave up. Upon receipt of the car it was such in good condition I decided not to part it out but to try and get it to start.

Now the black car I wasn’t driving and after letting it sit for a few years it had water and trash in the tank and it would not stay running. So I decided to pull the tank and clean it and also cleaned the entire fuel system. i also replaced the pump. Once I put it back together it would crank but not start. It was doing the exact same thing as the green car.

On both cars the fuel pump would not run unless you applied 12 volts straight to the fuel pump protection module (FPM). I have discovered that in the 94 Jags, and it could be in others, that Jaguar placed an extra fuel pump plug in the trunk that stays hot all the time that you can plug the FPM into and immediately test the pump to make sure it works.

On both cars once the FPM was plugged into the 12 volt always hot plug the fuel pump would run but it still would not crank. So I knew the FPM was good and that the pump was running but it still was not getting gas to the fuel rail. I checked and rechecked all the fuses and I found two fuses bad on the green car that caused the transmission relay socket and the fuel injection ignition on relay sockets not to work. the PO of the green car did not know that the fuses were blown or that the relay plugs were not working.

On the Black car all the relay sockets were hot but I wasn’t sure whether or not the relays were good so I purchased a cheap relay tester to test all the relays I could find on the car.

I found four bad relays in the black car and three bad relays in the green car. Once I replaced all the bad relays in the Black car it started right up. I have not tried to start the green car but I know it will start as it had the exact same problem. I also cleaned and checked all the grounds in the car.

Moral of this story for no crank/start issues is to buy a good quality relay tester and test all the relays you can find in the car. These relays looked smack brand new and they were bad. Also I had a limp home mode fault that went away as soon as I replaced all the bad relays. I replaced the relays with Bosch relays as there were just too many Hella relays that were bad.

Well done perseverance pays off.

Well done, Question… Are all relays the same or specific to each circuit?

There was a TSB issued on the light blue Hella relays, I replaced all mine when I first got the car with generic sealed ones.

Hi Dyna:

They are the same in that they are the can type 4 pin 30 amp relay. And yes they go to a different circuit. Also on the 93 and 94my cars there is a 5 pin relay under the hood amongst the 7 gang relay group.