BACKFIRING !

[andyhubbard]

Hi guys-a friend of mine as just replaced is HT leads and his Disco has started backfiring.It's a 3.9 with LPG conversion on a M plate,any help would be appreciated.

[smo]

Has he got them mixed up so its firing in the wrong order, or not fitted them correctly so fuel is not being burnt hence the backfires?

[Bob696]

when he has it fixed tell him to check the airflow meter as well. The gate is likely to be warped.

[thermidorthelobster]

Is it backfiring on petrol, lpg or both?

Is the exhaust OK or is it blowing?  Check manifolds for cracks?

If it backfires all the time, you could disconnect each plug from the dizzy in turn to see if it's one or two backfiring all the time.  But if it's only doing it occasionally, it might be a lot of hassle.

Are the HT leads decent?  Conventional wisdom is you need decent plugs and leads on LPG.

Are the carbs balanced and set up properly?

[andyhubbard]

Got the phonecall from the mate this morning asking if i could go and tow him back as it had cut out and decided to play dead.He had purchased new plugs and leads so we fitted these and at this point i noticed that his airflow meter pipe was not in line with the pipe to the chamber.Checked and the angled hose had completely split,checked local dealer and independants and placed one on order,the pipe is now gaffer taped back together and the car now runs OK.