HE v12 misfire

Author
Discussion

greg2k

Original Poster:

291 posts

240 months

Thursday 4th August 2005
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Cylinder 5 on the right in my XJS HE is refusing to work at all. I've recently had to change the left hand rocker cover gasket, which involves removing the left hand manifold, injection rail and throttle linkgae. Noticing that the old injector seals were taost, I replaced them, I also replaced the clips on the wiring harnace, calibrated the throttle linkage and put some injector cleaner in the tank.

There was a bit of grot in the recess for the injector seal but it was no different to the rest of them and they're running fine. Squirting WD-40 at the seal didn't change anything.

The injector is happily chicking away and fires fuel perfectly (removal and inspection) so I doubt the rebuilt harnace is the problem.

The spark seems to be strong and going into the plug not arcing.

The only thing that might be causing it is a stripped thread on one of the bolts on the injector fastening plate however I've pushed the injector down into its seal manually and nothing changes.

I'm really at a loss. It's either the seal being awkward, the plug acting up (or fouled by earlier misfiring) or something truly nasty. Anyone encountered this before?

milesj

15 posts

239 months

Friday 5th August 2005
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If your happy youv'e got a good spark and fuel supply, then rry a compression test...

jimbro1000

1,619 posts

291 months

Friday 5th August 2005
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Greg YHM

greg2k

Original Poster:

291 posts

240 months

Friday 5th August 2005
quotequote all
Fixed, It was a duff spark plug. I'd have expected better from NGK at £3 a cylinder.