VP stalls when idling on LPG

[toranamike]

I have a 92 VP dual-fuel and although it runs fine on petrol, it tends to stall when idling on gas. It seems to mainly happen when cold, eg the first few sets of traffic lights and roundabouts cause problems but after a while (with some revving at stop) it can idle okay. Also stalls in neutral.

Any ideas?

[m62vpute]

With a duel fuel car it is advised to start the cars on petrol and get them to operating temp before switching over to gas. If you just want to be able to start it first thing in the morning and run it on gas I would recommend in putting in a new set of spark plugs as gas is very hard on them.

[toranamike]

Yeah I don't start it on LPG as it just won't happen, but even after I start it on petrol and drive for 5-10 minutes it still is really rough and stalls when I stop, and no matter how long I've had it running it always stalls in Neutral when the revs get low... Not sure what to do :/

Do you think spark plugs would help?

[m62vpute]

Yeah I change my plugs when it has been used a lot on gas roughly every 35,000 to 45,000 kms. On the upside it is a cheap bit of matinance and it does not hurt to have a new set of plugs in. When was the last time they were changed???

[damselindistress]

The car may need a service by someone who knows gas conversions. Despite the fact that oil companies are now required to remove most of the petroleum (wax like substance) from LPG, it still tends to build up in your system and causes problems like the ones you've mentioned.

[mr calais 5.0]

I would pull a plug out and have a look at them.. Has the throttle body been cleaned latley as well.. I was told buy the guy that does gas conversions in bayswater that gas clogs the throtte bodies after a while..

[levymetal]

after doing the plugs it'll be worthwhile to get the gas tuned as well, your mixtures probably need adjusting if it's been a while

[noddycommodore]

If it was my car the first thing I would do I rip out the gas system since gas is only used for bbq's

[1_johnboy]

the gas has to be drawn into the motor via vacuum (assuming its a air valve system and not injected) at idle is when its at its lowest. Check all vacuum hose and in good order. There is a IAC "type" valve on most newer gas systems that can ritchen up and lean off the mixture. This valve may not be doing its job and low engine speed.

I would probably get a gas expert to check it out

[sawychri06]

my fatherinlaw does auto gas and my vp commodore is on gas, had the same problem when i got mine on gas. take it into a auto gas place and explain the problem mine just needed to be altered in the gas flow, just tunned up so it ran more gas on startup/ switch over then drop back down to normal gas flow after a few min
hope this helps