LPG Multivalve solenoid

mr_s · Post by **mr_s** » Tue Mar 27, 2007 8:39 am

Am I right in thinking that the solenoid on the multivalve (single hole tank, voltran multivalve unit) is supposed to cut the supply of liguid gas off to the rest of the system when the system is not 'active' and flowing gas?

I've got a strange problem with my LPG setup y'see, most of the time it runs perfectly, no problems at all. Then occasionally, when I restart it, normally when it's warm and try to flick over to gas, it either just dies, or sort of peters out, tries to keep running and then dies.

So I figured I'd remove the fuel shut-off solenoid in the engine bay and check the filter and check to make sure it is all working ok (I know that one is rebuildable!). But when I started to undo the pipe that feeds it, liquid gas came out. I left it a couple of seconds to make sure it wasn't just residual pressure in the pipe, but it kept coming....

Am I right in thinking that the multivalve/tank solenoid could be faulty (not shutting off, and possibly not opening properly sometimes)??

Cheers, Martin

p.s. Sorry if I rambled a bit...!

ChrisJC · Post by **ChrisJC** » Tue Mar 27, 2007 10:23 am

You understand right. There should be 2 solenoids, one on the tank, and one on the vapouriser. Wired so both have to be open for the engine to run.

Your diagnosis sounds plausible to me, sticky valve on the tank.
I've got a sticky valve on the vapouriser, doesn't always shut off, and hence smells as the gas in the pipe between tank and vapouriser leaks out of the air filter.

Chris.

mr_s · Post by **mr_s** » Tue Mar 27, 2007 11:09 am

Cheers for that Chris, glad to know I'm heading along the right lines

I have an extra solenoid inbetween the tank and the vapouriser on both of my LPG systems (flapper injection system on the Rangie, and Bosch KE Jetronic on the Merc 420), it's another 'filter and fuel supply shut-off' solenoid apparently.

It does lead to another question though - given that my tank is full of gas, is there a safe way of 'draining' the tank in order to replace the potentially dodgy valve (or at least inspect it!)?

I could just run it until the gas is almost gone (hoping that it mostly works...), but what about the last little bit that most likely remains in there? I don't really want to just vent it to the atmosphere..... lol

Cheers, Martin

ChrisJC · Post by **ChrisJC** » Tue Mar 27, 2007 4:27 pm

I've always just driven until there's not enough gas to drive, then let it idle until there's not enough for that, then vented to atmosphere with care!!

Chris.

diamond dave · Post by **diamond dave** » Thu Mar 29, 2007 7:24 pm

Yeah Chris, you're not far wrong with that. I worked on more "agricultural " LPG systems a lot of years ago & that's all we did when we needed to strip a system out.
I suppose someone will come in & tell us that this isn't allowed these days