1989 Jaguar XJ6

Engine Mechanical problem
1989 Jaguar XJ6 6 cyl Two Wheel Drive Automatic 110000 miles

i have a 1989 jaguar xj6 (3.6 motor I think), and it is randomly stralling, at idle or acceleration. Radio etc stays on but motor goes no where. Sometimes it starts right back up, sometimes it takes fiddleing with the distributor cap and sometimes it does come back on for a long time. I have done spark plugs(although gappin was wrong, so I re gapped), wires, dist cap, fuel filter, rotor button, and air filter. Please help me this is my wifes car and she will panic if she becomes stranded on the highway.
October 13, 2010.

I had a similar problem with my 81 xj6 4.2liter. It was running too rich and had to be adjusted, according to my mechanic he made a modification to the computer to control this.

Oct 10, 2011.
I would check the fuel pressure. There is a test port on the fuel rail. Most Advance or Auto Zone parts stores will loan out fuel pressure test gauges that come with adapters with a deposit.
Run it and get the specifications for your car with the vacuum line on the fuel pressure regulator and with it off.
I can probably find those specifications if you wnat them. Just post back and I will get back with them ASAP.
If the regluator makes no difference it may need to be replaced. If you can run the tester for a while without leaks, see if pressure flucuates or cuts out. If it cuts out the fuel pump relay might be bad. If it fluctuates the fuel pump might be at fault.