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VZ SVI LPG Ignition Problem

Weekend Warrior

Apr 7, 2008
Reaction score
Brishole QLD. Hopefully Gold Coast soon
Members Ride
Black VZ Wagon
Hey guys,
ok well i got my car converted to SVI gas about 5 months ago and im loving the savings!! Only problem is ever since i've had it converted it has a pretty terrible shake on idle, as in the whole car is running really rough and lean, kind of like it's about to stall. First up i got it checked out by the gas joint at it's 1500km service, got told it was the spark plugs, anyway i got the spark plugs changed about a month ago because one of the coil packs stuffed itself. Rough idle is still there. So anyway today i took it back to the gas place and the head mechanic spent an hour and a half looking over the whole gas system and he couldn't find anything wrong with the gas system at all. Here's what he wrote on the report:

"Vibration & stalling - Stalls on start using excess gas.
Check running rough/stalling on gas, found bad intermittent misfire at idle and just above idle on gas. Check gas system, replace injector nozzles and injector rail, check flow through injectors, test gas computer operation, test all electrical connections, all test OK. Refit original parts. Check system for fault codes - none present.

The entire gas system test is OK, suspect problem is caused by an electrical misfire caused by either a faulty spark plug, a spark plug with incorrect gap or a faulty ignition coil. These faults show up more when running on gas because gas is a harder fuel to ignite and will show up any problems with the secondary ignition system.

He then told me that he reckons i should take it to Holden because they should have tools to test the ignition system and see whats wrong with it, but before i go there and take out a loan to pay for their ridiculous labour charges i thought i might ask u guys what you think the problem might be. I find it strange that he reckons its the spark plugs when i just had the replaced... what would u guys do in my position?