Hi Guys,

I hope to get some of your thoughts about a problem I have. I think I know the cause but would like some reassurance. My AU Fairmont I6 backfired recently and I noticed that sometimes when I accelerate the engine numbers 4,5 and 6 spark plug leads were sparking across from the rubber boot to the cylinder head. As the spark plugs had a few K's, I decided to replace them and though that this had fixed the problem. However, this morning as I went to accelerate at an intersection, it backfired again. I bought new leads from Autobarm a few months back so I thought that they should be OK. Should I buy new leads or is there a way of checking the ones I have or is there possibly another problem.
Any advice would be appreciated. Cheers

If leads are sparking then they are bad. To test leads off the car set a multimetre to kilo Ohms and test each lead. No more than 1kOhm per inch is recommender but I refuse to use any that are much over 8kOhm regardless of length.

You do get bad leads in new packs. Best bet is to go to supercheap with your multimetre and make up the best set from their loose stock. They are normally Bosch and are ok.

cheers
Scott

if you can afford it get 9.0mm leads. LPG loves a good fat spark and the more you help it the better. check dizzy cap & rotor too.

also might be possible the LPG needs a good tune when was that done last?

Thanks Guys.
I take your advice and check the leads and replace if at all suss. Tune was done late last year and it was running great until I saw the leads spark. So I'll check leads first. Thanks

Falcongli, you need to get the "Spiral Coiled" leads they are designed for gas cars, you can get any brand you like, just make sure they are the spiral coiled ones, not normal linea conductors (a straight piece of wire like a normal cable), if your not sure ark for them, say that you have a gas car, if your at a half decent auto shop they should know what your on about, you can get the biggest and best hi performance ones you can find for you car and you will still have the same problem if they are not spiral coiled leads.......