What to warm up manually to switch to gas quicker

[Clifford Pope]

Are those pictures of iced-up vapourisers a thing of the past then or are they only in Alaska?

[daveherbert]

Originally Posted by FatLadZ

also youll find that you can gas start most multipoint lpg kits by holding the lpg switch on as you switch the ignition on and crank it.
I found this out the other day when i was telling someone about the time 2 years ago when i ran out of petrol in deep snow and had to walkk 3 miles for petrol!!!!
Much to this guys joy he told me all about it and was laughing

I can confirm what FatLadZ says is correct, well at least in my case. I have a 4lt ford explorer with a multi point gas system. After reading FatLadZ post I immediately tried it and it fires up on gas. no petrol used at all. prior to this I was using 2 gallon a week. 2 gallon in the uk costs me about £12 x 52 weeks will save me over £600 a year. FatLadZ I owe you a beer mate

[TomW]

Originally Posted by daveherbert

I can confirm what FatLadZ says is correct, well at least in my case. I have a 4lt ford explorer with a multi point gas system. After reading FatLadZ post I immediately tried it and it fires up on gas. no petrol used at all. prior to this I was using 2 gallon a week. 2 gallon in the uk costs me about £12 x 52 weeks will save me over £600 a year. FatLadZ I owe you a beer mate

Is it possible to carry out the above procedure with a V70 factory fit bifuel?

[Rversteeg]

Look at it from a LPG system manufacturers point of view:
Your engine is basically a petrol engine. On LPG the original ECU is tricked to let it think it is still running on petrol. To start a cold engine on petrol you need to enrich the air/fuel mixture, because some petrol will condensate in the cold engine and not be burnt. LPG is a gas and will not condensate in a cold engine, so mixture enrichement is not necessary. Because the ECU enriches the mixture as a standard, a cold engine on LPG will be running (much) too rich. What easier solution to avoid possible complaints about rough running than to start on petrol as a standard and to use the well tried out cold start strategy of the manufacturer? You also avoid problems with the original petrol system because it is regularly used. Other problems you avoid are frozen evaporators and starting problems because of a weak ignition system (LPG needs a stronger spark) which gave LPG systems a bad name in the past. On liquid injection systems (Vialle LPi) you also avoid the problem of ice particles in the inlet manifold, as a result of injection of liquid LPG (<0°C) into cold and damp combustion air.

My previous car (360) had a ring mixer type LPG system that was not connected in any way to the original fuel injection ECU. I always started that one on LPG, even during winters. I will never forget how easily it started on LPG after a very cold -18°C winter night, to jumpstart my neighbour with his new Renault diesel....
On my current 940 with Vialle LPi I like the idea that the petrol system is tested and "flushed" every morning. By the way, running a car on LPG with an (almost) empty petrol tank will destroy your fuel pump(s)! The petrol pump also runs when running on LPG!

[Herestandsaman]

Interesting thread.
I have 3 cars on LPG
The car to switch to lpg first is a custom system installed by classicswede on my 855R
Next is the Prins system installed on my C70
& worst is the BRC system on my v70R
BRC is crap, & so is their customer service.

[classicswede]

The BRC temp sensors are also different to all other systems. With the BRC software it is possible to lower the change over time and temperature but will all the other problems you have had with the system I don't think dropping the change over temp would be a good idea.

[knobstar]

I don't believe that running from start on LPG will have any adverse effects or even that it would be overly rich - surely the latter is impossible if you've got a closed-loop system? At least,on a closed-loop single point system it will always try to hit perfect stoich,will it not?
My system wasn't working great last winter but I intend to run it on just LPG this year :-)

[classicswede]

They run open loop on startup until the lambda has heated up

Also under load the injectors can freeze

[knobstar]

Fair points,though I guess very system dependant: I have a heated lambda (5-wire type); no injectors as such (just a tube into the throttle) and can also set the amount of time it runs open loop (it's a Leonardo).

[classicswede]

How have you connected to the lambda or have you fitted a separate probe as the Leo can not read a 5 wire probe. Cars with a 5 wire are also going to have the engine light on the time of running a mixer system as the mixture control is not compatible with them