The car is difficult to start when hot, usually after it has been sitting for 15-20 minutes after a good run. Sometimes the problem solves itself by flooring the throttle and turning the key, but then the engine pops and spits and only clears up by increasing the rpms, after which, the car runs properly again.
The right tailpipe produces black smoke during this process.
The CO2 sensors have been replaced, coil, wiring, plugs and distributor are all in good condition.
The above condition has existed for a couple of years, but does not seem to get worse.

Lex Vanwely
CXKJR
1980 XJ6
1991 XJS

Submitted by dougdwyer@eart… on Sat, 10/11/2003 - 03:12

Your description suggests an over-rich mixture. A few quick thoughts:

Injector(s) are leaking ---drip, drip----and raw fuel accumulates in the combustion chambers. of course, a cold motor loves the extra fuel but a hot motor can't tolerate it.

Coolant temp sensor "thinks" the engine has cooled down more than it really has and commands an enrichened mixture.

Fuel pressure regulator on the blink.

Hope this helps

Doug Dwyer