'99 Jaguar XJR X308 - Loss of power and poor fuel mileage
#1
'99 Jaguar XJR X308 - Loss of power and poor fuel mileage
Hello everyone,
I purchased an XJR X308 about a month ago or so and the car is acting up a little bit weird, here is my description of the problems :
- At idle the car vibrates a little bit, like a V8 diesel
- After driving the car for 10 minutes or so, I’m starting to have loss of power after 4000 RPM, and it gets worse and worse to the point where it acts like a rev limiter almost, but if I lift the throttle a little I'm able to get past these 4k revs
- In corners when the tank is filled at about a ¼ or less, the car has fuel starvation
- I get poor fuel mileage, about 15 mpg
The car has had a big service 2 ¼ years ago where they replaced the timing chains, fuel filter and plugs, and the car has only done around 8k miles since.
Also when I just bought it I drove it with the tank really low on gas. I removed the plugs and they seem fine with a brownish color.
I also put in a bottle of injector cleaner, didn’t help. But when I turn off the car and start it again I have no problem of power loss for 1 or 2 big accelerations and then they start reappearing.
Do one of you guys have already encountered these issues with your cars ?
Thanks,
Romain.
I purchased an XJR X308 about a month ago or so and the car is acting up a little bit weird, here is my description of the problems :
- At idle the car vibrates a little bit, like a V8 diesel
- After driving the car for 10 minutes or so, I’m starting to have loss of power after 4000 RPM, and it gets worse and worse to the point where it acts like a rev limiter almost, but if I lift the throttle a little I'm able to get past these 4k revs
- In corners when the tank is filled at about a ¼ or less, the car has fuel starvation
- I get poor fuel mileage, about 15 mpg
The car has had a big service 2 ¼ years ago where they replaced the timing chains, fuel filter and plugs, and the car has only done around 8k miles since.
Also when I just bought it I drove it with the tank really low on gas. I removed the plugs and they seem fine with a brownish color.
I also put in a bottle of injector cleaner, didn’t help. But when I turn off the car and start it again I have no problem of power loss for 1 or 2 big accelerations and then they start reappearing.
Do one of you guys have already encountered these issues with your cars ?
Thanks,
Romain.
#2
Hi and welcome Romain, can we please get you to introduce yourself in the New Member Forum and tell us a bit about yourself and your Jag (site requirement and rule review), it only takes a minute or two.... https://www.jaguarforums.com/forum/n...-intro-must-5/
No codes? ...restricted performance?
Could be a number of things, first off it sounds like a vacuum leak. Have you checked the SC Intercooler duct seals? You have a 21+ yr old car, vacuum lines will harden an recess from sealing properly around the mounting nipples...trim them back.
Could be a failing fuel pump, ...have you changed the fuel filter?
No codes? ...restricted performance?
Could be a number of things, first off it sounds like a vacuum leak. Have you checked the SC Intercooler duct seals? You have a 21+ yr old car, vacuum lines will harden an recess from sealing properly around the mounting nipples...trim them back.
Could be a failing fuel pump, ...have you changed the fuel filter?
Last edited by Highhorse; 05-26-2019 at 12:31 PM.
#3
Hi and welcome Romain, can we please get you to introduce yourself in the New Member Forum and tell us a bit about yourself and your Jag (site requirement and rule review), it only takes a minute or two.... https://www.jaguarforums.com/forum/n...-intro-must-5/
No codes? ...restricted performance?
Could be a number of things, first off it sounds like a vacuum leak. Have you checked the SC Intercooler duct seals? You have a 21+ yr old car, vacuum lines will harden an recess from sealing properly around the mounting nipples...trim them back.
Could be a failing fuel pump, ...have you changed the fuel filter?
No codes? ...restricted performance?
Could be a number of things, first off it sounds like a vacuum leak. Have you checked the SC Intercooler duct seals? You have a 21+ yr old car, vacuum lines will harden an recess from sealing properly around the mounting nipples...trim them back.
Could be a failing fuel pump, ...have you changed the fuel filter?
I've seen a vacuum line that was old and mellow and replaced it with a standard pipe. The idle improved for some time but then it happened again. I've seen that the threads in the screw that holds the big plastic intake part between the maf sensor and the throttle body had been damaged and it's maybe not as tightened as it should be, maybe I should delve deeper I to that as well ?
I haven't checked the s/c seals yet, nor the fuel pump. The fuel filter had been replaced 8k miles ago but I didn't change it afterwards.
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