Hi I have a discovery 2 V8 4L that runs on lpg it has developed a misfire on petrol I have replaced leads and I am going to replace the spark plugs (currently fitted with NGK R PFR6N 11 ) should I replace with the same? or any pointers to misfire please
Many thanks Al C.
Use NGK Irridium plugs, they list one for exactly this application. BKR5EIX-11. If it's an auto and the misfire is mainly as the autobox locks up in 4th at around 38mph, have the misfire codes read by Testbook or Rovacom or similar and see if 2 cylinders are misfiring that are common to a single double-ended coil pack, if so replace the coil pack - it's a common fault. (Common cylinders are 1 and 6, 8 and 5, 4 and 7, 3 and 2.) Badger.
Sorry its a manual gear box can I just confirm connections on coil packs looking at connections as if from inside vehicle, left hand coil pack top left 1 top right 6 bottom left
7 bottom right 4 . right hand coil pack top left 5 top right 8 bottom left 3 bottom right 2. symptoms of misfire are when you put your foot down from any speed it is spluttering ( on gas it seems fine, definitely more power)
Pass, I haven't got one handy to look at, and they can't be seen with the upper half of the manifold in-situ anyway. Rave is on other computer in workshop so can't check right now. Badger.
Fitted new plugs still the same :-( going to book it in to garage with correct diagnostic equipment ( even did an auto route mileage thing to your place............ lots..............). spose it is better than chucking lots of incorrect new parts at it. I will keep group informed ££££££££???????
many thanks Al C
faulty air flow meter....................Booked in for a fully sequential system did not realize how poorly my disco had been running
Al C
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