idle speed V8 LPG

[jasper110]

i have a 1985 3.5 V8 110 (low compression engine). i am wondering about the idle speed when running on gas(lpg) reason is that when ticking over at 700rpm, the amount of exhaust fumes is embarassing (you could hide an army behind it) i should note that it is about 4 deg C during the day at the moment.
if i turn the screw on the gas vapouriser in (clockwise, the smaller of the 2 screws ) until the idle rpm is 600, the 'fog effect' is less.

what should idle be on gas?

i realise that at lower temperatures the water vapour in the exhaust gasses will condense quicker until the exhaust has heated up, but it doesn't stop the rear view looking like a smoke screen.

cheers.

[jasper110]

come on guy's there must be some of you running V8's on LPG.

[Andrew]

Jasper I wouldnt mess with the settings on your mixer, because if you run the gas too lean you will most likely start burning valves etc, the condensation is a fact of life with gas, you are possibly best to run your engine a little rich., and put up with the smoke screen, as this will lessen your chance of overheating, watch your temp gauge , and if in doubt take your 110 to someone who can tune for gas.

regards Andrew

[byron]

i have a 1985 3.5 V8 110 (low compression engine). i am wondering about the idle speed when running on gas(lpg) reason is that when ticking over at 700rpm, the amount of exhaust fumes is embarassing (you could hide an army behind it) i should note that it is about 4 deg C during the day at the moment.
if i turn the screw on the gas vapouriser in (clockwise, the smaller of the 2 screws ) until the idle rpm is 600, the 'fog effect' is less.

what should idle be on gas?

i realise that at lower temperatures the water vapour in the exhaust gasses will condense quicker until the exhaust has heated up, but it doesn't stop the rear view looking like a smoke screen.

cheers.
Are you sure your coolant thermostat is opening ONLY at correct temperature?.....If coolant is too cool [or NOT hot enough] you won't be heating the LPG at the point where it changes to gas [sorry - forgot its correct name!] by the hot coolant......just follow the heater hoses to where they go to gas fitting device under bonnet.

Unless engine is running at correct temp AND coolant is hot enough to negate chilling of gas as it vapourises from liquid state it won't combust properly......Hence all the vapour coming out!

[jasper110]

Are you sure your coolant thermostat is opening ONLY at correct temperature?.....If coolant is too cool [or NOT hot enough] you won't be heating the LPG at the point where it changes to gas [sorry - forgot its correct name!] by the hot coolant......just follow the heater hoses to where they go to gas fitting device under bonnet.

Unless engine is running at correct temp AND coolant is hot enough to negate chilling of gas as it vapourises from liquid state it won't combust properly......Hence all the vapour coming out!


the thermostat is opening correctly, and the fumes don't have any smell of gas at all.
maybe an engine coolant preheater would be in order.
maybe i should emigrate to somewhere warmer!!!!

[byron]

the thermostat is opening correctly, and the fumes don't have any smell of gas at all.
maybe an engine coolant preheater would be in order.
maybe i should emigrate to somewhere warmer!!!!

If it DOESN'T smell of gas [or too rich a mixture smell] then it's probably just water vapour!.......Car exhaust has a lot of water vapour and having re-read the temps you're in (4oC) and it's in damp olde Scotland it's not surprising there's a fog behind you!.......RELAX- it's probably normal given the ambient temp and humidity!;)