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Thread: XKR 99 - Not Stating Intermittently

  1. #1
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    XKR 99 - Not Starting, Intermittently

    Hi Guys

    Hoping for a little help please.
    As title, my XKR 99 is not firing up intermittently.
    I notice there are a couple of lads having similar problems, but my starting issue is slightly different.

    The car has been running fine, however the other day while I was in Telford on a course, it would not start in the morning at the hotel.
    Turning over fine but not firing up. I called the AA and they arrived within an hour. The lad checked if there was fuel getting through to the plugs by removing one. It was bone dry. We had turned it over several times.

    He ask me to turn her over while he had his head in the engine bay. This time she fired up straight away. We were both amazed and I ask him if his middle name was Jesus, as he had not done anything other than lay his hand on the fuel pipe.
    I drove to the course and tried again at lunch break.
    Again she just cranked over not starting. Later near home time I tried again in anticipation of having get relayed home and she fired up several times no problem.

    So I drive back to Manchester without stopping in fear of a repeat. She ran perfect and accelerated as usual.
    Yet again fired her up several times once home no problems.
    This morning back to not firing up again, then later in the day fired up first time. All very frustrating.

    I've read that the XKR has 2 fuel pumps, I can see there are 2 relays in the boot fuse box. But looking at the parts suppliers I can only see 1 pump listed. Can someone clarify this for me please?

    Would a faulty fuel pump act this way or just fail altogether?

    Any advice would be much appreciated.
    Last edited by Gaaz; 07-04-19 at 10:18.
    99 XKR Convertible, Sapphire Blue

  2. #2
    Senior Member Jimbov8's Avatar
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    You do indeed have 2 fuel pumps. Figure 04.5 of this manual will help you check the supplies. http://www.jagrepair.com/images/Auto.../jagxk1999.pdf

    It sounds like you do have a problem the pump No.1.
    Jim.
    2012 XKR Black pack, Speed Pack, Aero pack, Rat pack. Past:-87'XJS 3.6L, 93'XJ40 3.2L gold, 95'XJ6 4.0L sport, 00'XJ8 3.2L sport, 2005 XK8 4.2L coupe, 2009 XK 5.0L Portfolio in that order and enjoyed all of 'em.

    I do not offer advice, I only say what I would do with the set of circumstances presented. Your choice always.

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    Senior Member Stumpy's Avatar
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    This may be of use to you. With thanks to WhiteXKR

    The early (4.0 litre) XKR has dual fuel pump design. There are two identical pumps in the fuel tank, connected in parallel (not series as has been erroneously posted). The primary pump runs constantly and the secondary pump kicks in under boost for added fuel volume.

    After discovering that I was running on just my primary fuel pump for months, if not years, on my 2001 XKR, I did some browsing through various threads on fuel pump failures. It seems as if many reported failures involved both pumps.

    I am convinced there are a lot of us driving on one pump. When the secondary pump fails there is some loss of power, but it is not 'in your face' dramatic and there is not a fault indication. When the primary pump fails the ECM is programmed to utilize the secondary pump as a backup. So in either case one pump will run the car.

    Since fuel pump failure is not particularly rare, every XKR owner should check periodically, perhaps at each oil change interval, that both his or her pumps are functioning. This will assure you have maximum power (ie; fun!) and also that you have a backup should one pump fail.

    In order to test the secondary fuel pump pull the primary fuel pump relay. Then try to start the car. The car will start and stall about half a dozen times, but eventually the secondary fuel pump will be switched to the backup role and then run the car normally from that point on. If this does not happen it is time to check the secondary fuel pump circuit (fuse, relay) and if they are OK, the secondary fuel pump and/or Link lead inside the tank has probably failed. (Of course, reinstall the primary pump relay when you are done).

    In order to test the primary fuel pump, simply pull the secondary fuel pump relay. If the car does not start you are already running on the secondary pump in backup mode, and the primary fuse, relay, pump or link lead has failed.

    Click image for larger version. 

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    Derek

    Current car
    2004 XKR 4.2 Coupé
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    1979 Daimler Sovereign S3 4.2L
    Why do most people with more money than they can every spend always selfishly grasp more?

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    Thank you very much guys.
    That gives me some understanding of the system and I will do some investigating over the weekend.

    Much appreciated.
    Gary
    99 XKR Convertible, Sapphire Blue

  7. #5
    Member KeithLyall's Avatar
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    Quote Originally Posted by Stumpy View Post
    This may be of use to you. With thanks to WhiteXKR
    Since fuel pump failure is not particularly rare, every XKR owner should check periodically, perhaps at each oil change interval, that both his or her pumps are functioning. This will assure you have maximum power (ie; fun!) and also that you have a backup should one pump fail.
    Stumpy,

    As suggested I went to test my fuel pumps earlier and whilst I found the relays in the black box in your diagram I couldn't see where the 5 relays 'Top up relay' through 'RH quarter up relay..' were located. Do I take it the normally aspirated version only has one fuel pump?
    Last edited by KeithLyall; 07-04-19 at 16:17. Reason: Misunderstanding by poster
    2017 F-Pace 2.0 i4 Diesel (180PS) Portfolio in Indus Silver
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    Senior Member astromorg's Avatar
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    Those relays are fitted outside the trunk fuse box, but you and I with our coupes do not qualify for any of them. One fuel pump is entirely adequate for our gentle Grand Tourers!!
    Last edited by astromorg; 16-04-19 at 17:07.
    2005 XK8 4.2-S Coupe and 2005 Auto SE 2.5 X Type Saloon

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  10. #7
    Senior Member Stumpy's Avatar
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    Yes, only the 4.0 R version has 2 pumps.
    Derek

    Current car
    2004 XKR 4.2 Coupé
    Previous
    1995 XJS Celebration 4.0 Coupé
    1986 XJ6 Sovereign S3 4.2L
    1979 Daimler Sovereign S3 4.2L
    Why do most people with more money than they can every spend always selfishly grasp more?

  11. #8
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    I'm really struggling to diagnose this fault.
    Problem being, one minute it wont fire, the next she fires up no problem and runs a treat.
    Full power, kick down, acceleration is spot on.

    I tried removing relay 1 and nothing happened, kept cranking without firing.
    Removed relay 2 and when she fires up, runs fine but get "Restricted Performance" warning.

    Fuses and relays appear to be in good order, I also tried hard reset.

    The only thing that seems to have any logic is it tends to not start when the ambient air temp is cold.
    If I start her up after the sun has warmed up then 9 times out of 10 she fires.
    If it is a bitter morning or evening, that's when the not firing comes back.

    It's a real puzzle, if my fuel pump was on the way out, would it not be consistently poor at starting?
    99 XKR Convertible, Sapphire Blue

  12. #9
    Senior Member Nerja's Avatar
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    Quote Originally Posted by Gaaz View Post
    I'm really struggling to diagnose this fault.
    Problem being, one minute it wont fire, the next she fires up no problem and runs a treat.
    Full power, kick down, acceleration is spot on.

    I tried removing relay 1 and nothing happened, kept cranking without firing.
    Removed relay 2 and when she fires up, runs fine but get "Restricted Performance" warning.

    Fuses and relays appear to be in good order, I also tried hard reset.

    The only thing that seems to have any logic is it tends to not start when the ambient air temp is cold.
    If I start her up after the sun has warmed up then 9 times out of 10 she fires.
    If it is a bitter morning or evening, that's when the not firing comes back.

    It's a real puzzle, if my fuel pump was on the way out, would it not be consistently poor at starting?
    That does sound like a bad fuel pump, with possibly only one of your two working. To be sure get a fuel pressure gauge and see what fuel pressure you are getting - they are cheap enough on Amazon.

  13. #10
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    Quote Originally Posted by Nerja View Post
    That does sound like a bad fuel pump, with possibly only one of your two working. To be sure get a fuel pressure gauge and see what fuel pressure you are getting - they are cheap enough on Amazon.
    Thanks for your advice Nerja.
    The AA guy that came out to me the first time it happened found dry plugs, before she fired up on the next crank.

    Are these fuel gauges you mention, specifically for vehicles?
    I have a gauge for water pressures at work, but wouldn't want to mix fuel with drinking water
    I had a look for the schradar valve mentioned but can't see it, can you give me an idea of it's location please.
    99 XKR Convertible, Sapphire Blue

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