LPG backfire Unleaded stalling ???

[oOSparkyOo]

My cars done it again after new leads been to mechanics just saying new leads the cars backfired (LPG backfires petrol stalls) and blow the intake pipe off its elbows and knocked the mapping sensor. This time hitting the tubes and making liquid come out not sure if coolant was dark at time i didn't drive my car hard and it just backfired pretty bad wtf is going on here

i recently got my exhaust done 1 day later (first) backfired seemed like tyre blow outs and took to mechanics where they just said new leads and remove an error code since then car stalls on petrol

(second) was just driving on LPG from Aldinga(SA) up hill backfire hanging in traffic had to try and put the elbow back on and drive home stalling on petrol

(third) time was with brand new LPG compatible leads just driving normally not hard and backfire again taking the mapping sensor off and moving it and unplugging the tubes underneath it making it leak

BTW ever since then the car will run on petrol then randomly stall
LPG now doesn't like to start straight away just stalling when started

any help will be nice i get my P's this week i need a car to drive and cant have my car causing problems like this as im pretty sure ill lose my brakes when i don't need to or be stuck in traffic holding everyone up.
im an apprentice so my money is low and the more i put into it the more im wasting because 1 problem after the other

[mrhotdog]

how old are your plugs? ive got duel fuel and was told to make sure the plugs are changed religiously and not left for 100,000km or something like that. may also to pay to check your O2 sensors as a dodgy earth caused shit petrol running for me, has ur gas been serviced/tuned recently?

[lil_mickey]

sounds like you lpg needs tuning or a vacume leak

[oOSparkyOo]

thx for your replies i recently got the car serviced before the exhaust but thye said they put new plugs in and all but can never be to sure

[Paiste402]

also its the gap of the plugs too since LPG needs a stronger arc to ignite the fuel.

[gontix]

I had backfire issues with my VR (but petral was fine). It turned out to be one of the coil packs. LPG seems to need a greater voltage than petral accross the spark plug gap, and the old coil couldn't cope. Try replaceing your coil packs one at a time to see if it goes away. Mine's never backfired since (I think I replaced 3/6 coil).