Mechanics

88 STARTS BUT WON'T STAY RUNNING

1988 Jaguar XJS • 68,000 miles

My 88 XJS V12 will start right up and run great for about 15-20 seconds. After that it sputters then dies. It seems like a fuel problem because I can sort of (I can only squirt 6 cyl at a time) keep it running with starting fluid. I've cleaned the injectors, and replaced the fuel filter and pump. The pump stays running until shortly after it dies. A timing light on the coil wire stays lit until it dies. The injectors are also firing until it quits. Any ideas?

Regards,
Marvin
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88kitty
June 25, 2012.




In my experience you have the most difficult car to diagnose made. Having said that would you consider yourself car savy? Electronic knowledge? Have a DVOM? Did problem occure after cleaning injectors? Try this key position II on DO NOT start press VCM on VCM/trip display. Check engine light will flash so flash pause flash, flash= 12


Docfixit
Jun 26, 2012.
Unfortunately the 88 XJS does not have a check engine light or a VCM button on the trip computer (see attached). I am pretty car savy and I do have a DVOM.

The car had been sitting for several years so that's why I had the injectors cleaned. I also had the gas tanks cleaned, flushed all the fuel lines and installed a new pump and filter. Prior to this problem I started the car about 10 times and let it run for several minutes with no issues.
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Tiny
88kitty
Jun 29, 2012.
Your right V12 no diagnostics so basic testing is needed. Exhaust backpressure, fuel pressure, crank sensor ect. My experience on Jag's in the 80's is that attempting to clean injectors results in there failure and replacement needed I found out hard way and had to eat injector for customer. You will need a manual for testing


Docfixit
Jul 20, 2012.

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