Page 1 of 2 12 LastLast
Results 1 to 10 of 18

Thread: Jag X300 hard tp start and stumbling when pulling away

  1. #1
    Member Freebird's Avatar
    Join Date
    Dec 2014
    Location
    Merstham, Surrey
    Posts
    39
    Post Thanks / Like

    Jag X300 hard tp start and stumbling when pulling away

    Hi all.

    My 3.2 has done 165000 miles now and has recently developed the faults in the title.

    I don't use it as much as I did since retiring so it can sit for a couple of weeks between runs. the first issue is that it has become difficult to start. It will fire then die several times before eventually chugging into life.

    Once running it idles ok, but when I accelerate, it dies and will stall unless I am very gentle with the pedal.

    My initial thought is a duff throttle position sensor, but am keen to see what others think - cheap they are not. I have cleaned the idle control valve (because that is more accessible) to no effect.

    Thanks in anticipation

    Glen.
    1996 X300 3.2 LPG, so cool.
    2005 BMW 330d Snore.......
    1969 Triumph Vitesse convertible

    1974 Suzuki GT550
    2000 Triumph Speed Triple 955i
    Merstham, Surrey.

  2. #2
    Junior Member
    Join Date
    May 2014
    Location
    Virginia, USA
    Posts
    6
    Post Thanks / Like
    Quote Originally Posted by Freebird View Post
    Hi all.

    My 3.2 has done 165000 miles now and has recently developed the faults in the title.

    I don't use it as much as I did since retiring so it can sit for a couple of weeks between runs. the first issue is that it has become difficult to start. It will fire then die several times before eventually chugging into life.

    Once running it idles ok, but when I accelerate, it dies and will stall unless I am very gentle with the pedal.

    My initial thought is a duff throttle position sensor, but am keen to see what others think - cheap they are not. I have cleaned the idle control valve (because that is more accessible) to no effect.

    Thanks in anticipation

    Glen.
    Have you cleaned the Throttle Body itself? Those tend to gum up on the inside.

    How about the MAF? Some MAF Cleaner spray might do the trick.

    Both are cheap fixes to common problems with these engines. I'm thinking its the throttle body. Take it off the car and clean it from both ends. Trying to clean it in place leaves the TPS in a vulnerable position as any cleaning fluids you decide to use, could enter the sensor and destroy it....assuming that it's not the problem already.

    After that, I might suggest spark plugs and coils.

  3. #3
    Member Freebird's Avatar
    Join Date
    Dec 2014
    Location
    Merstham, Surrey
    Posts
    39
    Post Thanks / Like
    Quote Originally Posted by Vee View Post
    Have you cleaned the Throttle Body itself? Those tend to gum up on the inside.

    How about the MAF? Some MAF Cleaner spray might do the trick.

    Both are cheap fixes to common problems with these engines. I'm thinking its the throttle body. Take it off the car and clean it from both ends. Trying to clean it in place leaves the TPS in a vulnerable position as any cleaning fluids you decide to use, could enter the sensor and destroy it....assuming that it's not the problem already.

    After that, I might suggest spark plugs and coils.
    Thanks for the suggestions - all very valid. I will have a go over the weekend and report back.

    Cheers

    Glen
    1996 X300 3.2 LPG, so cool.
    2005 BMW 330d Snore.......
    1969 Triumph Vitesse convertible

    1974 Suzuki GT550
    2000 Triumph Speed Triple 955i
    Merstham, Surrey.

  4. #4
    Member Freebird's Avatar
    Join Date
    Dec 2014
    Location
    Merstham, Surrey
    Posts
    39
    Post Thanks / Like
    Today the car started and ran fine which is typical as I had not done anything to fix the problem.

    I removed the TB and cleaned everything up thoroughly including the MAF. I removed the throttle position sensor to avoid flooding it with carb cleaner and used a multimeter to try to see whether it's dead or not. I think it is because it's open circuit between all three terminals except at nearly fully open when there is a resistance between two of them. At wide open, it's open circuit again.

    I put it all back together and it ran a bit rough to start with and now idles at 1500rpm in park and neutral but drops to 900 in drive.

    Answers on a postcard please.

    Cheers

    Glen
    1996 X300 3.2 LPG, so cool.
    2005 BMW 330d Snore.......
    1969 Triumph Vitesse convertible

    1974 Suzuki GT550
    2000 Triumph Speed Triple 955i
    Merstham, Surrey.

  5. #5
    Member Freebird's Avatar
    Join Date
    Dec 2014
    Location
    Merstham, Surrey
    Posts
    39
    Post Thanks / Like
    Hi All, I thought I would let you know that I cured my problem in case it's of use to anyone else.

    I fitted a thoroughly cleaned second hand throttle body complete with TPS and IAC valve and it made no difference, I then fitted a second hand MAF and that too made no difference. The previous owner had already fitted a new coolant temperature sensor so it was only a couple of years old, however I still had the original one, so I fitted that and all my problems went away.

    A bit annoying that I spent quite a bit of time and money chasing the problem around when I already had the solution in stock which took all of 3 minutes to fit, but you live and learn...

    Cheers

    Glen.
    1996 X300 3.2 LPG, so cool.
    2005 BMW 330d Snore.......
    1969 Triumph Vitesse convertible

    1974 Suzuki GT550
    2000 Triumph Speed Triple 955i
    Merstham, Surrey.

  6. Likes rick_shape liked this post
  7. #6
    Member
    Join Date
    Nov 2018
    Posts
    57
    Post Thanks / Like
    My X300 developed the same or a very similar problem & so did another X300 that I know of at around the same time. Sometimes it just would not start & at other times the engine would just cut out for no apparent reason. It made the car very dangerous to drive & because the problem was intermittent & never occurred when the car was at the Jag specialist repairers that I use, it took an age to discover the cause. On both cars, the fault was the same & was in the relay plug for the fuel injection in the engine compartment fuse box. The female connectors on the end of the wires are held in place in the relay plug by little plastic clips. One or more of those clips had failed & the wires had dropped down were only making intermittent contact with the male prongs on the relay. Once new relay plugs were fitted to both cars, they ran perfectly again. Trying to find the problem was a nightmare though. I threw money & parts at it, including new coils,, new fuel pump, new crankshaft position indicator & god knows what else. I was at the stage where I was going to sell the car to a wrecker when the problem was finally solved. I hope that this is the problem with your car as it is a simple & cheap fix. Best wishes, Craig

  8. Likes davidcumbria, rick_shape liked this post
  9. #7
    Junior Member
    Join Date
    Jan 2019
    Location
    Poland
    Posts
    7
    Post Thanks / Like
    I had the same problems with my car. I have checked the TPS voltages, changed all of the coils, spark plugs, crankshaft position sensor, swapped MAF etc. Finally I gave up and left the car with the Jag specialist. The problem was with the low fuel pressure. So now I am waiting for him to replace the fuel pump and fuel filter. With the fuel pump slowly dying, even moderate push on the throttle pedal was stalling the car or dropping rpms. The car should be ready on Wednesday, I will report whether the issue is solved.

  10. #8
    Member
    Join Date
    Nov 2018
    Posts
    57
    Post Thanks / Like
    Some years ago we had a company car with the same problem. It started & idled OK, but did not develop any power when the accelerator was pushed down. It too was a low fuel pressure problem at the injectors, but it was caused by a very dirty fuel filter. If the workshop have not already checked the filter, I would get them to do so before going to the trouble & expense of replacing the pump. Wouldn't it be nice if that was the problem & it saved you a lot of money. Best wishes, Craig.

  11. #9
    Junior Member
    Join Date
    Jan 2019
    Location
    Poland
    Posts
    7
    Post Thanks / Like
    You are absolutely right Craig. What I forgot to mention, is that the fuel filter was already replaced 2 months ago. That didn't help. I just assume that with the new pump it is wise to install new filter.
    The man working on it, reported there is a misfire on the 3rd cylinder. If that continues after the pump replacement, I will have to clean the injectors.
    Best regards, Michael.

  12. #10
    Member
    Join Date
    Nov 2018
    Posts
    57
    Post Thanks / Like
    Hi Michael. When I was chasing problems with my X300, I also changed all the coils, only to find that the car then also developed a misfire on one of the cylinders. In spite of the coils being new, one had a fault. If you still have the old coils, may I suggest that you fit it to cylinder 3 & see what happens. My specialist Jaguar repairer has told me that faulty new coils are not totally uncommon. If that does not help, a full bottle of injector cleaner into a tank of petrol might just do the trick, after you have driven it for a few miles. I use injector cleaner every 6 months, as I find that puttering around city streets does not keep the engine internals very clean. A good hard flog on the motorway may also help. Best wishes, Craig.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •