Hello all, was hoping for some insight.

I have a 2002 XJR with 135K miles. She's run great (with a few minor hiccups) for the last 4 years until today. She will crank and start normally, run for a couple seconds, then sputter and die. Can turn key OFF, then ON, and she will crank and start normally again, then sputter and die. I can hear the fuel pump run to prime the rails when you turn the key to ON. It's like she gets the initial amount of fuel needed to start, then the fuel supply quits and the engine dies.

I've searched and figure it's probably the primary fuel pump that has failed. I see I can pull the relay from the #1 pump and the car will then use only the #2 relay/pump and should start and drive, but with restricted performance. It would help me greatly to be able to drive the car (off highway) for a dozen miles over the next several days until the weekend so I can pull the tank and replace the pump.

If it is a bad pump, when I replace the pump and plug in the #1 relay, will any codes self clear, or will I have to go to a dealer?

I'd love any pointers on how to check the pump(s) and relay(s). I do all my own work, and know my Z inside out (had her 14 years and replaced pretty much everything on the car over that time), but haven't had to do much work on the Jag, so I really am totally unfamiliar with it, or where to find schematics, resistance values for the pumps, etc.

Thanks for any help/pointers/idea,

Mike

 

Hi Mike - I would start by changing out the fuel filter - especially if the last time it was changed out is "I can't remember". When you pull the fuel filter if you see dark brown or black particles/fluid - odds are the fuel pump is gone or on it's way out.

If you change out the fuel filter and run into the same symptoms - I would put my money on the fuel pump for sure.

Let us know your findings and good luck...

 

save heartache and change both pumps...

 

Been there, done that .. the second pump died within 20 miles necessitating a tow.

So only do it to get home, not to leave home.

 

Chances are that one fuel pump burned out long ago and the second one is now bad. Check your fuel pressure readings by connecting a fuel pressure gauge to the schrader valve on the left front fuel rail and see if your pressure goes down before the engine dies, if so , replace both fuel pumps.

 

No harm in pulling the relay to see if the fuel pump is the problem. I drove around like that until I could get to replacing the pump. You won't be able to rev past 3k rpm.

 

OK, I tried swapping the "fuel pump relay 1" relay with another relay and starting the car. No change in the starting, sputtering, and stalling.

Next, I pulled the "fuel pump relay 1" relay out totally and tried starting the car. Success! Starts and runs "normally", and I get the engine icon and restricted performance warning. Took her for a drive and all seems normal until you hit about 3K rpm and she shuts down hard; nothing subtle about it, lol.

Anyway, looks like I can limp the few miles I need to until I can fix things this weekend or next.

So, I'm pretty confident the #1 pump is toast. Anyone have a link to how to test the fuel pumps through the harness (relay socket) so I can doublecheck?

This forum has been invaluable in figuring this problem so far!

Thanks for any help,

Mike

 

You can try measuring the resistance of the pump windings at pin 30 of the relay and ground. If it reads high or is open you probably have a bad pump.

 

Well I only bought myself a few miles of driving.

Jag is DOA in a parking lot about a mile from home.

Will crank and fire, but wants to idle rough, and won't rev. Acts like it's starving for fuel. I only have an indicated 24 miles of range left, will try adding another gallon of gas. I was intentionally not adding any more fuel since I had to pull the tank anyway.

Did the other pump just decide to die, or is this indicative of some other type of failure that I'm not recognizing?

Thanks,

Mike

 

I do have a fuel pressure tester, but it doesn't have a quick disconnect fitting as I recall. It just has a Tee that you put inline with the lines.

Mike

 

Put more gas in the car (really shouldn't run it with less than a half a tank) - If you constantly run the vehicle with low gas level (less than 1/4 tank) your primary Fuel Pump is more than likely toast. I would invest $10.00 and change the fuel filter and see if that helps.

Think of it this way - if you need to change your fuel pump out you need to get that new fuel filter installed anyways... good luck..

 

Tried putting another gallon of gas in, no joy. Acts exactly the same, barely able to hold an stumbling idle just above stalling. Won't rev.

I plan on changing the pumps and filter this weekend if I can find all the parts locally.

Thanks,

Mike

 

My 03 XJR has the schrader, so I assumed yours did also. It is in the left front under the manifold on the fuel rail. I had to use a flashlight to find it. It had a gray plastic cap screwed onto it.

 

Thanks for the advice about pulling relay one . Just helped me get out of supermarket parking lot.

 

haven't seen many posts from Beady in the last four years or so!

 

The # 1 fuel pump turns on for 3 - 5 seconds to prime the fuel rail then back to off , then turns on again for the duration as the ECU sees engine rotation through the Crankshaft sensor .

You can have a partially failed Crankshaft sensor ( and is often ) and not have a CEL light or code or engine RPM showing 0 .

Since you have 2 pumps on the S/C engine you can hotwire to run at all times one or the other for troubleshooting before you open the fuel tank . Notice the location of the power fuses after the relay and not before .

 

I'm glad it helped.

I'd echo the previous poster about replacing BOTH pumps when you go in there. I don't know if I got even another dozen miles before the second pump failed. I used ford fuel pumps from autozone for about $90/ea at the time. That was 5+ years ago and they are (*technically) still running strong.



*Engine had catastrophic rod bearing failure a few months ago. She'll still start and run, but I figure a rod's about to make an exit through the side of the block if I keep pushing my luck.

 

I'm still around Over the last few years, the XJR has been every bit of what they say a Jag is.

In 2017 I had a water pump failure, a coil pack failure, 2 separate power steering failures, ate a tooth off the diff(!), then the last lower ball joint I had yet to replace started clunking the moment I backed out of the driveway to test drive the diff. There were one or two other failures, too; at one point I think I drove 12 day before she was DOA again. Then the rod knock started.....

Right now she's at ~165K and has a *really* nasty rod knock. I needed something else to drive this winter and and I was looking for a tatty, high-mile ~2000+ year BMW with a manual trans for about $2,000 that I could sell in the Spring and not lose much/any money on. But, I stumbled across a clean 1994 W124 E320 wagon with 93K miles that I couldn't say no to. I just wanted something to limp though the winter with, but I have to say I'm getting pretty attached to Dino, and the utility factor is through the roof with three kids.........









Not sure what I'm going to do with the Jag yet. Once it warms up I'll reassess if it's worth pulling the motor. Looks like I'd probably be better off rolling the dice on a used motor rather than spending more money trying to replace the bearings and the 100 other parts it'll need.