I have a 1998 XJR with excellent condition. Last time it suddenly died on me. When I checked the fuel pressure there was none. The fuel pressure regulator was good, so I removed the relay for the first pump and cranked the engine, to my surprise it worked with the second fuel pump. However the check engine light came on with p1230, Fuel pump relay malfunction code. I have verified that all relays work fine. my question's should I buy a new pump?
thx

 

I would test for voltage at the tank connector for the number 1 pump and if there is voltage there, yes I would change the one pump. Plenty of help on removing the tank. Check the archives.

 

on the XJR the fuel pumps work as follow:
When ignition is turned on, pump #2 is energized for about 2 seconds ( to built up fuel pressure)
When engine is cranked, pump #1 is energized ans stay on with engine running
Above a certain rpms/load, pump # 2 is turned on.

If the electrical circuit ( fuse, relay, pump) to pump # 1 is bad, the ECM turn pump #2 on and issue a fault code

Some notes:

If the car take more than 1/2 second to start, pump # 2 is not working correctly

If car feel slugish above 4000rpms or ping under WOT, pump # 2 is not working correctly

Changing only 1 pump is a big mistake, since the labor cost is the same for 1 or 2 pumps.
Often time the electrical harness to the pumps need to be changed due to overheating

 

That's exactly what the car is supposed to do with relay #1 removed.

https://www.jaguarforums.com/forum/s...949#post163949

You're probably looking at a bad pump, but theoretically, it could be the relay, the pump, or the wiring.

 

thx a lot guys, i'll be working on it this weekend and post the result. you guys are awesome thx again.

 

This might help if you see a need to replace the pumps http://www.gusglikas.com/images/Auto...eplacement.pdf It is for one pump but access is the same. The procedure is for xk but should help on the xj

 

Gus, I can't thank you enough !! the manual is well detailed with a lot of pictures, it's going to save me a lot of time and money by doing all the work by myself. thx alot!

 

i borrowed my grandpa's previous 98 xjr for a drive from long island, to albany, ny 1st rest area on the thruway, car wouldnt start to the tune of $1900 for 2 fuel pumps and relays

 

well i got lucky this time. i found a brand new BOSCH fuel pump for $45.00 on eBay and I paid $5.00 for the relay. overall coast $50.00

 

total cost $50.00 !!!

 

One thing I would buy is the plastic collar tools for disconnecting the fuel lines because your not going to get very far without them.
http://www.amazon.com/Lisle-37000-Co...sr=1-3-catcorr
It's a tank out job.
Disconnect the loom from the top of the tank.
Once you release the fuel lines from underneath, you'll need to pull the carpet, and undo the retaining bolts low down for the metal straps. Tie the straps out of the way, and pull the filler neck seal (expanding ring inside the filler that goes round the top of the filler neck).
You can then rock and role the tank out. It's a lot easier if there's little to no fuel in it. To get to the pumps you'll need a big screwdriver and soft head mallet to tap the retaining ring round and off. Pumps are at the bottom of the tank.

Hope this helps, and good luck