Hey All,

I bought a TH Wagon on Tuesday and had LPG installed on Wednesday. As I was driving around today I noticed the car shuddering / stuttering while accelerating (any acceleration will do it, gets worse the further your foot goes down). Took the car back to the LPG mob (who from my ringing around today are a very reputable installer and system) and they're saying it's a spark issue, but the car runs flawlessly on fuel (as far as I can tell) and only uses ~10.5L/100kms, so not excessive. They've asked me to take it to an auto elec, which I am doing, but has anyone else here had it? The only way I can really describe it is lack of fueling which I've had when my old car was missing a seal on the fuel pump, or when it had a split air hose inlet that was after the AFM

Regards

-Dave-

lpg is hard on ignition systems

need to check your plugs, leads, dizzy cap and rotor button

Most reputable LPG installers will change the plugs at installation. It does sound like either a plug problem or perhaps a problem with feeding too much or too little LPG. Good Luck and let us know how you go

spark plug dude i did mine changed to gas ones ie cooler rated and worked fine normally they would do this when they install the lpg but as i found out to save money etc a lot dont

So a little update.

I've replaced the plugs and leads and no change so it's off to an auto electrician. If they come back with the all clear I can then take it back to the LPG installer but I get the impression this is going to be a case of no one wanting to touch it and pointing the finger at other issues.

End of the day the car uses ~10.5L / 100kms on petrol with no stuttering / stalling / issues whatsoever so it strikes me as odd that it goes from perfectly fine to completely unusable when switching between petrol and LPG

Not a great response from a supposedly "respectable" LPG installer... They seem like a bunch of shifty bastards like all mechanics.

:(

-Dave-

If there is no probs when on Petrol then obviously it is the gas system that is doing this.
Would take it back to installed and demand they fix it or you will take it further.
Do you have a micer system or SVI?

that sort of thing is common on gas its USUALY an ignition problem or the tune is set way off for gas
mine goes bonkers every time i leave the lights on and get a flat bettery

mine goes bonkers every time i leave the lights on and get a flat bettery

Not sure what this has to do with his car running poorly on LPG?

The reason your car runs like crap when you have a flat battery has been covered many a times here.

If there is no probs when on Petrol then obviously it is the gas system that is doing this.
Would take it back to installed and demand they fix it or you will take it further.
Do you have a micer system or SVI?

Yeah I've taken it back once and that's when they told me it was a spark problem, I'll be calling OCBA tomorrow to see what my rights are as companies generally show a little more interest once you've spoken to consumer affairs.

I'm guessing on the horrible tune too, but it pisses me off that they expect me to get the car checked at my cost when it did (and still does) run flawlessly on fuel. I can't believe that LPG would be *that* intolerant that it would become unusable on a "problem" that doesn't affect fuel *at all*

As for the system, it's a vapor injection systems, not direct injection if that's what you mean, and it's a Megagas brand

One more thing, it runs fine when idling and revving, but under load it ****es itself which also leads to the poor A/F ratio idea.

do yourself a favour and check your dizzy cap and rotor for wear/burns/cracks.... this is the nature of lpg it has a higher dielectric property than petrol due to it being a drier fuel and requires a stronger spark.... a car car run perfectly on petrol and horse s##t on gas if the ignition system is worn

as for consumer affairs...good luck.... hope you like a paper trail that ends in frustration.... from my experience

Okay, so I've had the car checked out by an auto elec and he's replaced a grounding rotor button and checked the whole system out but can't fault it. Despite this he still believes it's an electrical problem as he's had the LPG system checked and it's running perfectly, not leaning off on load etc and the tune is apparently fine. He said the voltage coming out of the dizzy appears fine but still causing the issue and the only thing he can suggest now is to replace the whole distributor assembly to see if that helps. He's only charged me for parts so far and no labour, so I'm pretty happy about that but he's unable to get the distributor assembly at any of his normal suppliers so I guess I've got 2 questions for all you genius types :)

1. Does this all sound plausible (I'm fairly convinced as everyone appears to be telling me the same story, all independent), and

2. does anyone have a dizzy assembly in good condition they'd like to sell me?

TBH if I'd known it was going to be this much of a PIA I'd have just lived with the 10.5L / 100kms I get now and saved myself the $1050 it's cost me so far :(

Thanks

-Dave-

Looks like I need a new AFM and air filter as well. All the backfiring from trying to get the LPG system appears to have blown it apart.

Here's a pic of the air filter and the honeycomb from the AFM, with the AFM plugged in the car idles like crap but when I pull it off it works fine so I'm guessing the whole thing is fubar :(

http://sithicus.net/DSC00333_resize.jpg

OH SNAP !!!
thats nasty

if you take it somewhere and they cant fix it they shoudlnt be charging you !!

rip it up em !!!

They didn't charge me (only for the parts they did actually replace, no labour), but it no longer runs on petrol which it at least did before

yeh this is why i had VSi fitted

so after you get your replacement AFM invest in a champion distributor cap.... they only $90 odd bucks compared to genuine article for $160 and look like they outta the same factory

i'd try the cap before getting a complete dizzy as it dont play up on petrol and as i said earlier gas is harder on the ignition system
also what plugs and leads did you fit

and after all this it will need re-tuning

question is tho why didnt the installer fit an anti-backfire plate

Someone from the forum is offering up a complete dizzy for $50, should I go that way or go for the new champion cap only?

Awesome it'll need retuning, I'll be taking it back to the same place and scream at them till they tune it for free, and while I'm there I'll ask them why they didn't install and anti-backfire plate :)

-Dave-

the problem with the dizzy's is the caps pit too much for lpg after about 50,000 km resulting in misfiring/back firing, you could try the complete dizzy.... but i've not replaced a single dizzy on a 6g7x motor in all of my 12 years as an autosparkie.... id still try the cap first.... if the dizzy ws rooted then you'd feel it on petrol too... or have a car that cuts out/wont start