Hi, A few weeks ago I purchased an LPG converted run about, First one I have ever had, It starts on petrol and when warm switches to LPG, today it won't switch over, is this to do with the cold ?

Never had one of these before,

Cheers
Scooby

may sound really stupid, and i mean no insult, but have you checked there is still LPG in the tank?

i know that the petrol acts as a reserve when the LPG runs low.

should still switch over, but can take a lot longer. Ours switches in a few seconds in the summer, 5 mins this weather. If in doubt take it to an LPG specialist, they are usually very good!

I bought two LPG LWB Transit vans with LPG three years ago, and they wouldnt switch over when the LPG was empty.

The solenoid valve on the tank can stick in very cold weather.
It's the same type of valve as the one in the engine bay, but doesn't have lots of lovely heat around it.
The criteria for running on lpg are both solenoids open, signal from petrol injectors to gas ecu to allow timing for gas injectors, signal from lambda sensor, temperature within range specified in tuning, lpg level above cutoff level. Provided the switch on the dash asks for running on lpg, all should be good.

Yep, Its full of gas, filled it yesterday, Its a pick up, so the tank is on the outside below the bed, so very much open to the cold.

Will see how it behaves tomorrow, found a local lpg station to fill it up, who also do the conversions, so they can check it.

The switch on the dash, is a simple push button with a red light, the red lights on, and before as soon as the engine was warm 4 green leds came on to say the tank was full and it was now on gas.

Cheers

Another thing to consider is how advanced is the system, mine is a late sequential system which also wires into the petrol tanks fuel sensor and blends petrol with gas to lubricate the valves.

The system monitors both LPG level and fuel, on the basis that if it runs out of petrol two things will happen,

1) the car will be 100% gas but a weak mixture so not good

2) the fuel pump and injectors will run dry and burn out, very bad

So in my car a low petrol tank will also stop it running on LPG.

You need to also check its got antifreeze, LPG takes longer to switch in the cold as the vaporiser is heated, usually teed in to the heater hoses, if these pipes are frozen it will not kick in.

Rather than spend £££ down the LPG garage I suggest you get the correct programming interface from Ebay for £20, and log in to the system, you can then see how hot the vaporiser is set to come in and how hot its getting, in reality you can usually set down to 15degrees and the car will be fine as long as you do not tax the engine when its still relatively cold.

What system have you BTW

Regards Mark

Im not entirely sure what system I have, These are the details from the LPG certificate.
Tank Stako
Regulator PRINS
Eguipment Supplier ALTERNATECH

I Checked and added Antifreeze last week, I have also topped the fuel level up by a fiver,

What does the programing interface do ? and how do I use one ?

Cheers

If you chase the wires back from the regulator you will find an ECU, this could a a little chap or something bigger, either way it will have a serial lead that you plug into a laptop so can set the system up.

linky thing

It may not be a prins ECU, although the chances are it is but check.

Stako is a high end tank manufacturer

Once you have the interface you should be able to run diagnostics on the system and view the parameters, on the one IO have you can force over to LPG, trip the valves, ping the injectors etc.

Regards Mark

Cheers Mark

Hi there, as this is locost forum before you spend any money try this. As there are no green lights showing and you know the tank is full it could just be the float in the tank stuck ! Get a nice piece of wood and give the tank a good whack and see if that free`s it
HTH Paul.

what sort of pickup, as in EFi or a nice old carb one
could make a big difference!
But as I said, the small independant LPG places tend to be reasonable on price and good on knowledge.