Club 80-90 Forums

Having read through the posts in this section, it seems as though running on LPG can be improved by disengaging or, completley removing the warm air unit and blocking the vacuum tube to the carb. Does this affect the performance when running on petrol, i.e, Cold weather starting, carb icing, etc. I don't want to remove it if it will degrade the performance/reliabilty when switching to petrol. Many thanks for a very useful forum.

AngeloEvs wrote: Does this affect the performance when running on petrol, i.e, Cold weather starting, carb icing, etc.

In a word 'No'

Our's starts and runs on gas from cold, given the chance I let it warm slightly before setting off, partly because we're straight out onto a steep hill and partly 'cos I'm a nesh old git IIRC the warm air unit is for like -10c and below.

Steve Gasure removed our warm air unit, 'cos that's where our evaporator unit lives. I assume he takes them out anyway ?

Ian.

Many thanks Ian!

Same here - steve took it off and it was a bunch of rust anyway!

Starts fine even up here in the Highlands coldest days......and we have had -8 this winter

Yep our warm air unit is removed too.

Point though, you asked if this affected running on petrol.

I think the replies you have got so far confirm that cold starting on gas is fine - and I agree with that.

However, when the LPG conversion is fitted it is normal to fix the choke "fully off" permanently and when starting on petrol I find this does affect starting and running from very cold. It takes a bit of pumping the accelerator to get some fuel in via the accelerator pump and a bit of gentle jiggling the right foot to keep it going, but only for a couple of minutes. Once it is even vaguely warm it runs fine.

As to carb icing, one would think that removing the pre heater for the incoming air might cause this, but so far I have not experienced it. Perhaps it might only be an issue if you are in the middle of a Swedish winter ! I guess our warm engine bays, with the carb sitting on top of a hot engine and our relatively mild winter temperatures ( compared to some countries ) make it not an issue.

there is no reason to remove the choke, for when you start from cold on LPG you keep the throttle open whilst cranking,
on petrol you drop the pedle, which closes the choke, then crank.

that said, mine never had the warm air thingy, its was a injection, which i changed to carb, and ive never had icing.

and ive never had icing.

well thats the last time i buy you yum yums

Never been a problem really on my syncro.. runs on petrol and no warm air intake.. during the cold weather it means letting it run for a couple of mins to warm up a fraction, but I know the idle mixture is set quite low in anycase...

LPG... no need to remove or cut the choke.. either adjust it so its not so shut, or just use a little throttle when starting... I always used to turn ignition on with throttle open, when lpg valves click off (timer, 2-3 seconds) then turn off and turn on again small throttle and start... this primes the inlet with a slug of gas...

Thanks guys, very helpful. I never thought about altering the choke but assumed that no choke mod is necessary if your happy to start on petrol and then switch over to gas when the engine warms up?

No need to mod the choke...

my caravelle was always started on LPG for 5 years.. just use a fraction of thottle to get it going..