LPG Temperature problem

[Boxster1]

HI

I have a Mk7 transit with a Landi Renzo LPG system.
Its worked perfect for about a year. However during the recent cold spell, after the usual 5 mins warming up it would switch from petrol to LPG.
Resulting in a missfire and I had to manually switch back to petrol. Even when the temperature gauge showed that the van was up to temperature there was still an LPG missfire.
After constantly trying to run on LPG, it was only after about 30 mins that I could switch to LPG and fire on all 4 cylinders. Then it would run perfect all day.
This happened every day during the cold weather.

Now that the weather has warmed up, the switch over occurs after about 5 mins and we fire on all 4 cylinders.
Any ideas anybody ?

Mike

[madmart132]

you might be low on coolant ?
The gas is so cold that it will freeze the vaporisor if there is not enough warm water going through the cooling system , they need the hot water to turn the gas back into a liquid form
I have a BMW 5 series and when filling the radiator on Saturday I could actually see the vaporisor and surrounding pipes freezing up ,once properly bled the ice melted and everything returned to normal .

[the dutch guy]

First guess would be that the evaporator is gunked up with coolant crap so it never gets hot enough.

[Boxster1]

First guess would be that the evaporator is gunked up with coolant crap so it never gets hot enough.

Hi The Dutch Guy

Thanks for your reply.
Not being very technical I don't fancy pulling the evaporator apart.
Could I get away with draining the coolant and then flushing ?

Regards
Mike

[madmart132]

possibly a flush will help , the basic idea is the water in the engine warms the gas so it can be injected in to the manifold give it a try and get back to us even try a hosepipe to the waterpipes in the vaporisor

[midnight]

Hi, With regards to the coolant. If the coolant is at the correct level then check the antifreeze content of the coolant. If the antifreeze content of the coolant is too low then you will need to add more antifreeze. I mix my own coolant at 33% antifreeze and I have no problems with the vaporiser freezing.

[Boxster1]

Thanks guys
I will flush the system this weekend.
And then refill with 5 litres of red antifreeze.
And will report back next week.

[the dutch guy]

there is a large hex bolt on the front of the evaporator. as long as you dont turn that thing you wont break anything.

take out the entire thing in one bit and use a hose and clean it out. good indicator is the hoses going to the evaporator.
if you ont see anything then check the flow.
use a temperature probe (steal one from the kitchen of needed) and measure the temperature of a metal part of the engine block and compare that to temperarure of the evaporator. they should be basically the same if its not evaporating. then check the temperature when you are running on lpg and check again. it should still be well into the 50+.
if the temperature takes a dive it means there is not enough flow and there is some kind of blockage.