LPG OMVL idle screw on 3.5l V8

Hi everyone. I just finished the conversion to LPG on my V8 and I have some questions regarding the adjustment screws on the OMVL r90e vaporizer. In the instructions it says to close off the idle and adjust it with just the Sensitivity screw to get it to run properly first.

My question is this: i adjusted the Vaporizer to work at idle and on the road perfectly on just the Sensitivity screw. The idle is shut. It runs fine and goes perfectly on the motorway. I have a 60l tank and with 48l of lpg it gives me about 90miles of range before it looses power.

My engine is running on SU dual carburettors, nothing fancy.

So what is the point of the idle? Should I just leave it shut and forget about it?

Can't help as regards the vapouriser idle screw but your mpl is very low.
Are you using gas rings?
Do you have a way of adjusting the flow - either at the vapouriser or something in the vapour lines?
I wonder if it's running rich.

Mine's a 3.5EFi. Initially with a gas ring but then fitted a BLOS. I average around 2.8 mpl empty or full & towing so 48 litres would return around 134 miles.
I have a flow adjuster in the vapour line, basically a tube with a big screw at right angles. You turn the screw in & out to adjust the max flow. If you have a gas ring at each carb you would need something like this:
https://www.econovagas.com/en/product/gas-flow-adjuster-plastic-016-x-012-x-012/

I dont have the mixers, as I ran out of budget, so I made my own. They are crude and not very efficient so the low mpg is propably due to that. Will install good ones when I can.

Dont have a flow valve as it comes with the rings. Will do all that when have some more cash.

I should however mention that my car is a 1991 DAF Leyland Ambulance - Automatic, which I converted to a motorhome. It weighs over 3 tons.

fgcity said:

I should however mention that my car is a 1991 DAF Leyland Ambulance - Automatic, which I converted to a motorhome. It weighs over 3 tons.

Click to expand...

Ah, that might have an effect on the consumption!
That said, I get around 2.8 mpl even when the car's loaded to the roof with a 17' boat on a trailer. Boat & trailer weigh almost 1300 kgs.
So I think proper rings & a flow valve when you can afford them might help.

I had no idea how much efficiency I should begetting from the beast, but based on my numbers I already cut the expences to half as it was just guzzling fuel before. I do know it could be more efficient though. Atleast now I can use it instead of dredding every hill

Seems the problem was elsewhere. The multivalve i got, had a short intake tube. So there was still 1/3 in the tank which I wasn't using. I emptied the tank and added a gas tube to touch the bottom. Its been going for 120 miles now and there is still some left. I will however still get proper mixers when I get a chance.