LUMPY RUNNING

[KEVIN47]

HI EVERYONE
I HAVE A 1989 V12 CONVERTIBLE, WHICH STARTS FROM COLD FINE BUT ONCE I START MOVING ALONG ENGINE RUNS ERRATIC THE REV COUNTER NEEDLE JUMPS AROUND ALL OVER THE PLACE , ICANT HEAR ANY MISSFIRING BUT PULLS AND SURGES , IHAVE USED INJECTOR CLEANERS TO NO AVAIL , THERE SEEMS TO BE A CONSTANT SMELL OF PETROL IN THE CAR , BUT NO WORSE SINCE I BOUGHT IT A YEAR AGO
CAN ANYONE HELP ME PLEASE
P.S. I HAVENT CHECKED ANYTHING YET
REGARDS KEV

[STEVE121SILVER]

hi kevin are you sure its fuel related i dont know as much about the v12 but i had a simular issue with my 4.0l changed the cam sensor and the temp sensor now purring as it should dont know if its any help but good luck. steve

[supersnipe1979]

Hi Kevin,
Sorry, can't help you with the 'lumpy running'. I'm still trying to sort my idle problems out. However, the smell of petrol you mention reminds me that i had the same problem in my 3.6. The fuel tank had a very small fracture around a spot weld and leaked fuel into the rubber/sponge pad supporting it. Apparently XJS tanks are regular offenders in this repect. A real pain to do (the tank sticks in place) but i'd take the tank out and check it. If it's leaking you might try Kent Jaguar at Sevenoaks. They had three s/h tanks in when i replaced the tank on my 5.3. not long ago. Good luck, Mark

[KEVIN47]

Thanks for the advice chaps,

I will look at both your suggestions.

Have already checked the spark plugs and tapped the injectors as the main dealer mechanic suggested. Wil keep you informed if I have any luck.

Cheers, Kev.