LPG Not Getting Through to Engine

[I Love My Landy!]

Hi all,

Currently on a road trip and the gas supply to the engine suddenly cut out. The car is an 84 110 V8 with CID carbies and Impco gas converter. The two solenoids in the engine bay are working, as is the gas fuse. The solenoid on the tank seems to be working (there is no easy way to check the current but it does 'tick' when the gas switch is on). I cannot hear the louder 'thunk' that the tank usually makes when the gas switch is turned on. I believe this is the valve on the tank opening? I disconnected the gas line between the tank and the solenoids in the engine bay (with the gas switch on but with the engine running on the remaining unleaded in the carbies) and no gas came out.

I refilled the tank even though i was sure i still had more range left, and it only took 58 litres out of 65 useable, so there was still gas left.

I assume the problem is the valve sticking or broken? Are there any DYO fixes for this problem, or is it a specialist LPG mechanic job?

On a related note, this happened about 3 weeks ago. I refilled the tank and it only took 58 litres and the valve did not cut off when the tank was full, the gas flow simply slowed down until the flow almost stopped. The car started and ran properly thereafter though.

Thank you,

Edward :)

[bee utey]

Underneath the outlet valve on a LPG tank is what is called an "excess flow valve". It is there to shut off the flow of LPG if all the other external valves fail, eg are broken off in a severe accident. However, they can occasionally slam shut if the electric valve opens from a hot tank to an empty service line to the engine bay. Normally they reset all by themselves once the flow is completely stopped. What I suggest you do is turn off the tank outlet tap, double check that there is no gas in the line, then dismantle the electric solenoid. Check that the plunger is free to move in its brass tube, and has no damage to its rubber face. With the solenoid removed, CAREFULLY open the service tap a crack to see if any gas come out. If it does, shut the tap and reassemble the mechanical part of the solenoid valve. Be very careful to see that any o rings aren't damaged. A slight smear of liquid detergent, silicone grease or even spit will help. Now apply a strong magnet to the end of the valve, before you reattach the coil. You should hear the plunger move to the open position. Open the service tap very carefully and allow the line to fill. Reattach the electric coil and test the system for leaks. In an emergency the solenoid plunger can be left out of the valve assembly but it should be seen to as soon as possible. I've seen the occasional plunger lose a tiny core of rubber out of its middle due to the pressure exerted on it in hot weather, they are then a throw away as they just jam up on the seat, not letting gas down the line. The brand of valve that does this the most often is AMR, an Australian brand.

[I Love My Landy!]

Hi bee utey,

Thank you for your detailed reply. I did what you suggested. With the solenoid removed i opened the service tap and no gas came out.

I now recall having this same problem many years ago. My gas mechanic said upon removing parts from the tank that a filter or something dropped into the tank. He said that this may foul the gas flow. I haven't had a problem for years so i almost forgot about this. Just in case i gave the unit a decent tap with a rubber mallet but got no result.

Anyway, i'll take it to a mechanic and i'll report back.

Thank you again.

Edward :)

[I Love My Landy!]

Just a quick report on the problem. I was about to drive to the mechanic when i thought i'd try the car on LPG just one more time. Surprisingly (well, kind of - nothing really surprises me in a Land Rover anymore) it fixed itself. We'll see how long it lasts for!

Edward :)