Hi Folks,

4.4V8 petrol 04 plate (with LPG conversion)

I have a misfire that is intermittent, as far as I can tell it only happens when the car has sat out in the sun and is warm -- this misfire appears to correct itself as soon as it switches to LPG, any thoughts please?

Many Thanks

lpg usually shows any weaknesses in the ignition system so if the issue is only on petrol it suggests an issue with petrol delivery , maybe a petrol injector playing or gumming up , try running on petrol for a couple of days and see if the issue disappears

Thanks Dingg,

Just been for a run, and it's very lumpy, i930 reports misfire on cyl 8 -- now I had bank 2 apart yesterday, well to the extent of checking and contact cleaning coils, oddly 5, 6, and 7 sprung nicely and needed the nuts to sit on top of the plug, 8 onthe other had sat down and stayed down, noe whilst the spring looked good I was running out of time and couldn't see the top of the plug -- I was only there checking for oil ingress etc.

To be fair it could be missing on LPG too, I suspect the LPG interrupt system maybe fooling the engine ecu that it is firing correctly.

All other thoughts welcome

news.......... ran with no misfire today, very curious, still hay to listen to suggestions

Update: -

the problem only appears on bank 2, cyl 5. 6. 7. or 8

From start up in hot weather it misfires, faults are stored, as soon as it switches to LPG no faults stored, now I suspect the LPG electronics is fooling the systems.

Any thoughts please?

Further update -- changed the hoses on the PCV -- touch wood, seems ok!