Any Ideas, trouble filling up with LPG

[stevepage3]

Hi

I have recently aquired a 3.9v8 Disco which has 2x 35 litre LPG tanks under the sills.

My problem I have run the car until the LPG system says it has no gas and switches back to LPG but when I try and fill up it will only let me put 28 litres in which I assume is only one tank.

Any ideas.

Steve

[jimthelandyman]

You will never be able to fill the tanks right to the top, i'm assuming that this is to allow the gas to expand in the tank? I think its some safety thing anyway. My 80 litre tank will only hold 64 litres.

[barnhill4x4]

Are the solenoids working on both tanks? Sounds like one isn't opening.

[stevepage3]

Sorry guys

but this is first Lpg car I have had, I understand that if I have 2 35 litre tanks that would give me 70 litres and I would only be able to fill to about 60 litres.

The problem I am having is I can only fill 28 litres which I assume is 1 tank full of the 2 and the second one will not let me fill it. Solenoids ? what are they where are they ?.

Any other ideas or info on how this works..

Steve

[Range Rover Blues]

It depends how your system is fitted but as I understand it you can only have 1 tank "open" at any one time, so that if you have an accident and roll the liquid phase can't run out of one tank into another.  As stated there must always be about 20% "ullage" above the liquid phase (the LPG that has condensed due to the pressure).

Now 28 litres sounds about right for one 33 litre tank.

So, either you aren't getting all your tanks connected, or the valves in 2 of them are stuck somehow.  As a guide the tank that is emptying might feel colder than the other 2 :-k

It's also possible that you have a blocked filter and the LPG system switches back to petrol way too early because it thinks you are out of gas.  My multipoint system monitors the LPG pressure in the injector rail and if it falls too low then it cuts back to petrol.  It does it a lot when I get over-enthusiastic :oops:

Could be ready for a good service.

[dxmedia]

Don't rely on the gauge! To say that they are inaccurate is an understatement. Run it till you need to start accelerating to keep at the same speed (running low on LPG is different to running low on petrol), then switch over and fill up.

If it still only taking 25L then you've a soliniod not opening on the multivalve on one of the tanks.

[listerdiesel]

The solenoids for the multi-valves are on the tank itself, small black plastic moulded things with a red and a black wire coming out.

They are rated for 12V not 14V so they fail open-circuit after a while. I had one go down last year and bought 2, keep one as a spare.

They are held in place by a single M4 nut and washer that is under a plastic cap, all on top of the valve.

I'll try and find a picture that I took of mine when I changed it.

There is a mechanical shut-off on the filler that stops when the liquefied gas is at a certain level, nothing sophisticated, and that is approximately 80% of the full tank capacity.

Ours has 2 X 33 litre Stako tanks, we get 48-51 litres on both, depending on the filling pump. Newer pumps tend to fill more than the old ones.

Peter

[Rossko]

Wot he said about solenoids.

To clarify from earlier, they are both opened at the same time ; there is no changeover arrangement.

It's practically impossible to determine if you have one tank that won't fill - or one that won't empty.  Both are possible faults.  But given that the outlet is electrically controlled, thats more likely.  You might have a lie down and get an assistant to switch fuels, listen to see if both valves clang.

The wires to the two solenoids are probably spliced under the car somewhere; splices exposed to road salt are good failure candidates as well.  Push-on connectors at the solenoids can go green.

Most sill tank solenoids are inaccessible without dropping the tanks out, so it might turn into a saga yet.

[stevepage3]

Ok finally had some decent weather so was able to go for a crawl under the disco !!

when I switch over to LPG both solenoids one on each tank can clearly be heard to click so assume the solenoids are not the problem.

The LPG gauge is wired to one of the tanks with the connections on the other which I assume would also be for a gauge not connected does anyone know what
resistance I should expect across the terminals is this tank was full of LPG.

I still can only get 28 litres of LPG in which is the amount I would expect for one tank. any ideas why the other tank is not working ?

Thanks

Steve