XJS 4.0, engine idles on cold, but slowly dies if warm

[Sasha]

Hi there,

I am looking to buy a 4.0 l 1992 Manual XJS. the oil cooler was replaced, and drives nice. Engine sounds ok.

But there is difficulty starting the engine without pressing the throttle.

Also, engine idles ok, but dies out slowly when car is warm till it cuts out.

when forced to start, by pressing gas, fumes come out of exhaust on intervals when throttle is pressed,,

Could you advise me what could be wrong with it? milage is 150K.

I thought it could be the temprature sensor ... Car does not overheat.

help, please!
regards,
Sasha,

[Jon]

Sounds like its running rich then. I assume the fumes are black rather than blue.

Is there any smoke when driving? I think as you say the temp sensor could be a possibility.

If it didn't drive nice I would have suspected the air flow meter.

The throttle bypass valve could possibly be at fault, this would stop the engine idling properly but it would be OK in normal driving.

Are there any fault codes displayed on the trip meter?

[Sasha]

Thank you very much for your reply, Jon,,

The trip computer didn't display any codes, but it seems every time I lift my foot off the throtle, it stalls when warm, even when stoppin in a traffic light. The owner says it happens every now and then, but during the test drive it did it all the time and he had to rev it when shifting,,

regards,
Sasha,,

[dhdove]

Sasha
How much is the car, in what condition..........?
There are hundreds of XJS's out there, a lot with lower mileages.
Unless you feel you have to buy this car because it's a steal I would suggest you ask the owner to sort it out at his expense and test drive it when he has done so.
In the meantime go and look at some others.
DH Dove

[Mark_B]

there's a thread on here in 'engines' called 'car stops =/' which might be of use.