This year, after retiring I have the time to really get behind the wheel and drive my Jag almost every day and now things that I have lived with have begun to bother me and I need to get them fixed!!

First issue is that I have a hopelessly pessimistic fuel gauge. When I fill the tank the gauge correctly shows at full, however after consuming just 12 gallons of fuel, the gauge is already in the red and by 13 gallons the low fuel light comes on even though my fuel tank is supposed to be 21.6 US gallons. By the time I get to 15 gallons consumed the needle has passed the E on the gauge and is resting against the stop which is a bit disconcerting. Fortunately the trip computer seems to measure fuel consumption fairly accurately and I have carried on driving till the computer read 19.5 gallons consumed. (not brave enough to go further ) So what do you think could be causing the problem?

Second issue is with the parking break light which I know has been an issue for many XJS owners. The handbrake works perfectly, engaging when I pull up and able to hold the car easily on a steep grade. It releases fully when I press the button and lower the handle but when initially starting the engine, the handbrake light will not go out until I have driven around for about 5-10 mins. No amount of button pressing or handle jiggling in that time will make the light go out, however after the initial time period has passed the light goes out as soon as I press the button. If I stop the car and engage the brake, the light goes on and then if I release it goes off. Very weird, surely the light can't be on some kind of delay timer? I would think that something is sticking but it's just weird that it happens this way every single time. Any ideas?

Thanks,

Allan

 

Sorry, didn't mention, it is a 1994 XJS 2+2 Conv.

 

Not savvy with the "update" cars, but sounds like the fuel sender float arm needs reshaping to get the correct ratio to the dash unit.

This is a major pain on the early cars, their gauge is even more pessimistic, if it worked at all.

The floats sometimes get fuel ingress, but that usually gives a "low" reading when full.

Handbrake light, PASS.

 

Clean up and adjust the micro switch on the handbrake lever. Seat out is pretty essential to do this!

As for teh gauge, no substiute for new sender, I found. Then work carefully through the system, including the gauge in the cluster and its electricity path (palm's book excellent in this (pre facelift). I did all of the above and the gauge is perfect.

Greg

 

Thanks chaps.

I'm going to replace the sender and see if that does the trick. It seems as though it might be a calibration issue, does anyone know what the output range of the sender should be?

As to the handbrake, how does one adjust the microswitch?

Thanks,

Allan

 

There is a small screw that holds a plastic square cover over the handbrale fulcrum. Under this is a microswitch, operated by the fulcrum lever, that makes the circuit to light the warning light. Have a bit of a fiddle with this microswitch and see if some working it/adjusting its position/WD 40 or contact cleaner type treatment does the job.

It is just nearly impossible to get to it with the seat in position, that's all.

Greg

 

The micro switch depends on the cable pulling back on the release of the hand brake. You may also need to check the rear arms that the cable works on the rear suspension. If they are stiff, then the cable does not retract and the switch is not opened. I think there should be some spring that pulls the arms together. It could also be the switch adjustment if there is to much gap to the switch arm, then releasing the brake does not turn it off.