Please help if you can

I have an XKR, vintage 1998-9 and I love it.

She would not start last week, I thought it was because she was low on petrol and I had parked her on a steep slope (long story) and that the fuel was not reaching the feed.
I put a gallon in but to no avail.

I called the AA who towed me to a flat piece of ground but she still would not go.
The AA diagnosed a faulty fuel pump and towed me to the local garage (not a Jag dealer).

The garage fitted a new fuel pump (twin pump variety).

The car now fires up runs for two or three seconds and stops, almost as if an immobiliser is cutting in.

The garage got the local Jag expert out who said that his diagnostic computer could not speak to the CPU in the XKR.
The Jag expert suggested putting it on a low loader and taking it to a Jag dealer so that they can replace all of the CPU units, one at a time, until they diagnose why the reader cannot speak to the CPU. This is at an estimated cost of £1200 per unit (plus towing!).

Has anybody had this problem or know of a possible cure. I love my car and am trying to run a supercar on a budget and can ill afford the fees implicated.

I have trawled the web and found two suggestions.
Firstly to connect the negative battery lead to the positive terminal to do a CPU "reboot".
Secondly to check the wiring on the fuel pump is not backwards so that the high pressure pump is working instead of the low pressure pump.

Any advise or suggestions would be so gratefully received.

Many thanks

Mike

 

As you said, there are two pumps. Did they replace both?? Did they replace the "in tank" link harness?? They typically burn up, and should be replaced while doing the pumps. I ALWAYS recommend replacing BOTH pumps, and the harness. I'm guessing they did not. First thing to check is B+ and ground to the pumps at the harness that goes to the flange upon cranking.

 

I would sure NOT replace any modules until someone diagnosed and troubleshot the pumps. I wouls also steer clear of the person who encourage changing modules, unles sther is mor eto the story tah they told you or you are telling us. Module replacement is way expensive. If one thought a module was "hanging the network", which is HIGHLY unlikely, one should unplug modules, not replace them. Somebody has their head where the sun don't shine.

 

Hi Ross
The advice I have been given is along your lines. The diagnostic computer cannot gain any information. The blame seems to be lying with a module and the advice is to unplug each module one at a time to find the rogue unit.
I would love to know if there is a quick fix by rebooting or maybe it is that the new fuel pump has been incorrectly fitted as described in Jagtec1's reply.

 

Hi Jagtec1
The pumps are whirring and fuel is getting to the engine.
Before they were fitted there was no fuel getting through at all.
Could this be an engine management issue as the engine seems to fire up really well and runs normally for a few seconds? It then appears that something is killing the spark.
Many thanks again
Mike

 

Mike: Get a fuel pressure test guage and find out what is happening on the fuel front. As to the network hang, try another scanner. I t is always possible that the scanner was acting up. BTW, what scanner was it?

 

Yup, what is the pressure at the rail upon cranking? What about 3 seconds later?

 

I am doubting it will fix your problem, but a full reboot is quick and easy to do yourself. Remove the negative batterey terminal first. In your case to guarantee all modules reboot, turn the ignition full on. Then hold the negative terminal to the positive terminal for a few seconds. Then turn off the ignition. Then reconnect the neg. battery terminal. Wait a minute or so and try to start.

 

Thank you for your replies.
Car still not sorted. One fuel pump changed and no result. Jaguar dealer said that there is only one fuel pump in the tank so got an independant dealer to check and they confirmed there are two!
I am being to ld that he second pump is part of the tank and will cost £1200.00 for a new tank and pump!!
There must be a solution to this. I am very reluctant to spend another £1200.00 plus vat plus labour to possibly end up with the same problem.
If anybody has any ideas then please help, my car is worthless sitting in a garage and I am reluctant to scrap her.
Mike.

 

in curious to know what diagnostic tool your expert used,if it was an autologic,gig touch screen looking thing i would defiantly not go based off that recommendation,i would investigate basics,checking fuel psi and making sure that both fuel pump and link leads were replaced with genuine one not some aftermarket trash.i cant tell you how many i re-do for customers that come from independent repair places that use substandard parts or lack of replacing both pumps and harnesses

 

Dear All
I can't thank you enough.
Jag mended and running better than ever.
It would seem that one fuel pump (the one which is tough to get at) failed a while ago and the other pump managed to work for a while before it gave out too.
Once both pumps and harness had been replaced (with genuine parts - thank you tech4jag) it ran beautifully.
The main dealer quoted me £1200 for a replacement tank which was unnecessary. Thank you for your advice Jagtec1.
In short, this forum guided the car repair place brilliantly, got my car going and saved me a fortune in the meantime.
A great success story and as you can probably tell I am delighted
Regards
Mike

 

great to hear of a positve outcome.

just for my own curiosity, what could have caused the first pump to fail?

 

It's very common for the fuel pumps to fail on these cars. Often times the secondary pump will fail and will go unnoticed as that pump is only on past around 3500rpm. When the primary pump goes out the car will not start and that's when the car gets towed in.

I don't know why the dealer told you that you will need to replace the entire tank just for a fuel pump on this car.

 

Is it that some cars run with low fuel levels - could increase the possibility of pump failure

 

I was very low on petrol and parked on a lateral slope, half on half off of the road.
I was convinced that the fuel was not getting to the feed due to the slope so put my spare can in and pushed it onto the flat. I think that turning over the engine without fuel did not help the pump at all.