Help with LPG

[stevejo43]

Hi

I was curious as to whether anyone has had any probs with lpg and knows what to look for and where? Is it likely I have damaged something? Was out picking up my other half today when "bang". Hasn't run properly since. Found one hose off that operates some lever and found that it blew my air filter down in its box. Don't know what it is. Runs fine on petrol but stopping at the lights on gas

[xrayxray]

LPG is sensitive to bad spark so try leads,plugs,coils yet will run fine on petrol.
also LPG backfires if running to lean so try oxygen sensor or poorly fitting air inlet hoses or filter.
Too many backfires will damage air flow sensor as well.
Good luck with it.
Cheers Mickey.

[Bradtot]

Would help us if you could tell us what vehicle carby fuel injected etc etc.
as has already been said if injected can damage the airflow meter but I would look for another hose off somewhere as u say its ok on petrol.
Brad

[sam_d]

Stop running on LPG straight away and don't use it again until you've had it looked at. As XRAYXRAY says LPG is sensitive to any dodgey elements in the ignition system so get that fully checked out.

If you keep running on LPG and you keep getting frontfires you run a high risk of ruining your MAF sensor (and they ain't cheap to replace) or even worse, a fire in the air filter box. :o

[PAT303]

One thing with LPG is you have to run the right leads and plugs or the problem will never go away.I have had three gas powered vehicles and they all needed low resistance electrics to work.My present Disco hasn't missed a beat since fitting,I don't know why it isn't part of the job. Pat

[Lotz-A-Landies]

Steve

I don't know your system, however I also had problems on my LPG EFI running rough at low revs and stopping at the lights. The problem turned out to be a small vacuum line at the rear RHS of the plenum. Replaced the tube onto the nipple on the plenum and it ran fine ever since.

Would still get everything else checked out, but if you had a backfire it is also likely that this little tube came off at the same time.

Diana

[stevejo43]

Found the tube, cut it because it was a loose fit and I changed the coil. A little improvement but running a bit better than it was before she went bang. I remember looking on here somewhere where someone said to look at the engine running in the dark. I did this and saw little sparks at the base of plugs and on the coil lead around the power steering pump was dully lit up around the circumference of it. It definitely must be the leads. Funny that they are top guns and they don't look that old. Looked in super cheaps yesterday but they didn't have any kits and they told me I need top gun MAX. Does this sound right. What are the best possible leads to buy so they don't arc out on things?

[rovercare]

Top gun leads are poop, how new? dont expect alot of kays out of plugs and leads on LPG anywhere down to 30-40,ooo:eek:

You want big, fat, low impedance, leads, just go into your local Bursons, repco etc and ask what they stock in the realms of that:)

[scarry]

steve
have run some of our work vans on lpg so have learnt a lot about it over the years. hope the following helps
1 always use very good quality leads we always use genuine ones & they last at least 100000k. u wont even get 20000 out of cheap ones , & then u will get another backfire
2 replace spark plugs regularly & use good quality
3 lpg is very sensitive to air leaks on air filter box & inlet manifold.after a backfire check airbox is ok hoses on etc.
4 also get gas tune from someone who is good at it as if it is not done properly & it runs lean u will have lots of greif
5 fit new airfilter before getting gas tune as lpg systems are very sensitive to air flow.if u dont do this & replace the air filter later on down the track it will not idle properly
6 we use an ocky strap around the air box after the 1st backfire as the hold down clips break seems to work well

we used to have more trouble with the older carby vans but with the later fuel injected ones dont have many backfires or any other problems

many of our vans have done over 200000ks on lpg with no probs at all not even a backfire

happy motoring:):):) :):)
paul

[markd2]

hi all

everything that has been said and also check the rubber hose from the plenon tothe air flow meter (maf senser) as sometimes the backfire can split this hose remove it and check it can split at rib underneath and very hard to see if not removed. also if you have an idle mixture screw on yourconverter open it a little will increase flow at idle and stop it from being so lean.

cheers mark

[stevejo43]

I will definitely get into Repco when they are open and ask them for some quality leads and some plugs> have checked all hoses, seems to be fine. I did have to use a few screws for the airbox though

[chazza]

I have had a good run with Gasmaster leads and Iridium spark plugs so far,

Cheers Charlie

[pgf]

HI,Same experience as others. Old plugs and leads (>30k) bang bang bang. New NGK 8mm leads and new plugs (gapped down a few thou). Runs like a beauty.

[stevejo43]

Fixed the prob. New plugs New Leads, New Coil and mucked around with the gas valve. Idles good now except for when I get to about the last 20 ks of gas left in tank