Can anyone offer any advice? My car is stuttering when I try to accelerate. It is fine when the throttle is wide open, but if I am in say 3rd gear at low revs and apply medium pressure to the throttle it stutters badly (continually), sometimes it eventully sorts itself out, or if a put my foot down further to wide open it goes fine.

I don't think it is anything gearbox related as it still does it even when I lock the car in say 3rd gear.

It happens with the traction control on and off, although I do have a new fault (as off last night), a traction control curcuit fault,  basically the switch does not work and feels depressed (not unlike the owner!!!). Maybe something to do with this, but still happen with the information screeen says the traction control is off....?

Only other faults are that two light bulbs have blown, one between the clock and the oil pressure guage and on the left hand side of the climate control screen where the tempeture is displayed.

My daignostics software is not reporting any other faults.

Can anyone offer any thoughts of what I could look for??

Many thanks

Jon 

Sounds like it could be fuel related, contamination or a blocked injector maybe? It might be worth trying a fuel treatment, which you put in the tank just before you fill up.
Just my stab in the dark

Dan.

I think it is unlikely to be water in the fuel tank.  However, if it is, there is a cheap and simple remedy.  Just add some pure alcohol to the tank.  Alcohol is water soluable and will carry the water in a combustible solution out of your fuel tank and through the fuel injection system.  It will burn like petrol and your problem will be solved.


Gary the Viking
USA
1997 XK8 coupe
1994 XJ6 Vanden Plas (XJ40 Daimler 4.0)

I have booked it into a jag specialist to do a diagnostics test. I have the full autoenginuity software, but still can't find anything other  than the electrics fault.  I reckon it need the rest of the coils done and the gearbox reprogrammed. I am off on holiday at the end of the week so it will be a couple of weeks before I get to find out!!!

Thanks

Thanks for all the suggestions, back from holiday and the local jag dealer has had the car for a week - they have replaced both the door seals so hopefully I am now water tight!  My rear tyres have arrived, I went for the sport contact 2's to match what I have already.  The jag dealer have reprogrammed the ECU to fix the lean fuel problem - I drove 1.2 miles before I have restricted performance and a P0171 fault code !  So the car is going to the local independant jag specialist on Thursday, they can have a go at fixing it ( and fit my new tyres)!!!

I am gettig used to the feeling that this is a difficult problem to resolve and probably not a quick fix, I need to get lucky that something I get done makes the deifference. This is so different to the x-type I owned previously which just worked all the time without fail. 

One day it will run properly, I am determined that I will beat it and have it working as it should!!!!!!!!!!!!!!!

Just a thought. It’s always easy to be wise from afar! I had something similar on my XType which turned out to be a combination of plugs and coils. The diagnositic equipment showed up a "lean burn" issue. I replaced them all and all is now fine. These things do seem to have a life expectancy of between 70K to 80K and have a tendency to play up if overlooked.

Hope it gets sorted soon

Nick

Hi Jon, Full marks for tenacity - the hallmark of a true enthusiast! - and if I was lucky enough to own an XKR, I'd be persevering too. Cheers, Archie.

Just jumping in and am not sure what already has been tried, but here are some possible causes for the P0171 error:

-      Air intake leak between MAF Sensor and cylinder head
-      Fuel filter / system restriction
-      Fuel injector restriction
-      MAF Sensor fault (low intake air flow)
-      Exhaust leak (before catalyst)

This type of error is generated if the standard fuel trims are above/under when driving in closed loop. So a not so good working lambda sensor could also be the issue, at least not something to rule immidiately out, though it is not so common to fail on suchh a young car imo.

It would be interesting to see what the short and long term fuel adaptations are for both banks, this is something you can read with the Autoenginuity tool. Best would be to drive steady in closed loop, and  record the 4 parameters. You can also test the fuel pressure if you have the tool with Jaguar option.

If it would be 1 cylinder with the problem, you might be able to see the difference in colour of the plugs, though you may have to do some WOTs to be out of closed loop for a while.

Checking for air leaks should be easy, and also swapping a MAF sensor, so these things should certainly be thoroughly checked before swapping over other things. Not sure how you could test an exhaust leak though.

Hope this helps,
Andre.