1998 XJR running issues
Discussion
Hi - Was wondering if anyone has had these niggles before?
I've had a 1998 XJR for nearly 4 years now and to be honest she has been an absolute dream. 90k - FSH which I keep up to date at a main dealer.
I'm getting a few irritating things happening lately. Only now and again - which is even more frustrating as I know the moment I take it to the garage - it won't happen.
1) Driving at around 50 - 60 mph the car will sometimes feel like it is missing - put your foot down and go a bit faster and it disappears.
2) The tick over can sometimes briefly be lower than normal or higher than normal.
3) Sometimes the car seems to be driving itself - I slow to a halt and the car seems to want to drive forward - like the throttle is sticking, but if I slip it into neutral the revs drop to normal and do not stay high as expected, although they seem slow to drop to the right level.
I have a suspicion it could be the throttle - is there anything I can do myself to rectify the problem or is it a garage job?
J
I've had a 1998 XJR for nearly 4 years now and to be honest she has been an absolute dream. 90k - FSH which I keep up to date at a main dealer.
I'm getting a few irritating things happening lately. Only now and again - which is even more frustrating as I know the moment I take it to the garage - it won't happen.
1) Driving at around 50 - 60 mph the car will sometimes feel like it is missing - put your foot down and go a bit faster and it disappears.
2) The tick over can sometimes briefly be lower than normal or higher than normal.
3) Sometimes the car seems to be driving itself - I slow to a halt and the car seems to want to drive forward - like the throttle is sticking, but if I slip it into neutral the revs drop to normal and do not stay high as expected, although they seem slow to drop to the right level.
I have a suspicion it could be the throttle - is there anything I can do myself to rectify the problem or is it a garage job?
J
It may be a problem developing with the earlier type of throttle body. These were subject to a recall under warranty until quite recently on earler cars when driveability and occasional stalling were reported. This recall is no longer live but it's been suggested there may still be some goodwill from Jaguar due to the potential seriousnes of a sundden loss of power.
One thing you can try is to carefully check all the breather pipes are clear and the butterfly inside the throttle body is not heavily contaminated with oil or a build up of deposits. If it is then a through but gentle clean inside the body and butterfly valve with carburettor cleaner and an old toothbrush may be all you need. Whilst you've got the breather pipes off the cam covers very carefully clean the 2.5 mm calibrated hole in the part throttle breather pipe stub on the LH cam cover with a 2.5 mm drill bit - by hand and with real care - making absolutely sure you don't open up the size of the hole beyond 2.5mm.
As a long shot it may be worth replacing the fuel filter in case it's partially blocked and causing fuel starvation and checking the drain pipe in the petrol filler cap is clear. Water can acculmilate in the filler cap recess and get into the petrol tank when the filler cap is removed if the drain is blocked. Just pull the little black plastic tower off in the filler recess and clean it and trickle a little water down the pipe to ensure it's clear.
One thing you can try is to carefully check all the breather pipes are clear and the butterfly inside the throttle body is not heavily contaminated with oil or a build up of deposits. If it is then a through but gentle clean inside the body and butterfly valve with carburettor cleaner and an old toothbrush may be all you need. Whilst you've got the breather pipes off the cam covers very carefully clean the 2.5 mm calibrated hole in the part throttle breather pipe stub on the LH cam cover with a 2.5 mm drill bit - by hand and with real care - making absolutely sure you don't open up the size of the hole beyond 2.5mm.
As a long shot it may be worth replacing the fuel filter in case it's partially blocked and causing fuel starvation and checking the drain pipe in the petrol filler cap is clear. Water can acculmilate in the filler cap recess and get into the petrol tank when the filler cap is removed if the drain is blocked. Just pull the little black plastic tower off in the filler recess and clean it and trickle a little water down the pipe to ensure it's clear.
Jaguar steve said:
It may be a problem developing with the earlier type of throttle body. These were subject to a recall under warranty until quite recently on earler cars when driveability and occasional stalling were reported. This recall is no longer live but it's been suggested there may still be some goodwill from Jaguar due to the potential seriousnes of a sundden loss of power.
That was my thoughtNew from Jaguar they are something like £1,000
I do have a new one at home if you require it, a lot less than that, eMail me if you do fine that is the problem
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