Xantia LPG issue

[Sid_the_Squid]

Hi all,
Having an LPG issue, not directly citroen related, but its on my xantia.
To summarise; after much testing, I belive the issue is the gas not leaving the rear tank, possibly due to blockage, possibly due to rear electrovale not opening on command.
I've had most of the under bonnet stuff off to check for issues, but I've never touched the tank being slightly afraid of the 45 odd liters of compressed propane.
Sadly I dont have any kind of documentation regarding the tank, so really dont want to be 'stabbing in the dark' and unscrew the wrong thing, or supply power to the wrong place.
I might be talking utter bunk here, but I think theres a rear electro valve in the tank which should be opening to let the gas up front to the front electrovalve/filter before hitting the vaporiser/reducer, does this sound about right?
Second question if the above is true, would there be any danger supplying a 12v current direct to the rear electro valve, it could be stuck or prehapse a wire break somewhere between the control system in the engine compartment & the tank.
Third question, assuming duff electro valve, what can one do? it is replaceable without draining the tank?

Thanks

[HDI]

There will be a gas shut off solenoid valve on the tank. All the tank connections etc are normally in a box on the tank with a detachable cover. Can't really see a problem with trying a 12 volt test feed to the solenoid.
Replacing the valve would require the tank to be empty.
Have you tried to listen for the valve clicking in and out when starting ?

[deian]

ohh scary stuff gas is, i don't like changing the gas tank on the forklift at work, the valves leak often on them cos some idiot has over tightened the screw and broken the seal

is this the citroen xantia 1.8 that comes with factory fitted dual fuel?

[HDI]

Nah , we had a gas truck in our family business and cylinder changing was a never an issue. As long as the cylinder is turned off before the cylinder is removed there should never be any danger. Explosions are pretty unlikely because the pressure in the cylinder would eject the gas before any ignition source could reach inside.

[Sid_the_Squid]

thanks for the replys, heres an update of the situation.
I am now almost sure its the rear cylinder cut off solonid which has stuck closed. I've checked the other two cut off valves (one in the filter, one in the reducer) I can hear both click open\closed, however on the tank valve I applied a 12v direct feed to it, and nothing, no click, no sound of gas going up the feed pipe. I think its dead even worse it now looks like I've got to throw away a full tank of LPG to get fixed .

To answer your question deian, sadly no this is an aftermarket job, fitted by the previous owner, who judging from the workmanship appears to be micky mouse.

Thanks for the input, guess I've just got two petrol xantias until further notice.

[HDI]

Check with an LPG installer to determine if there is anyway the tank can be emptied and then the gas re-used. They must have had this problem before ! Have you checked the power feed to the valve ? If there is a power feed when there should be one it's probably the solenoid coil thats failed.

[aerodynamica]

Hi, I have an LPG CX so am familiar with some of the same things on your car.

First thing that no one has mentioned: there is a manual shut off on the valve block on the LPG tank: it is some sort of knob that will be located on the multivalve (solenoid, level sender etc.) near to the shut off solenoid you mention. It's used for working on the pipes/valves and/or for removing the tank. Also useful for when the car is stored long term.

Please find this first and wind it in before you go activating the tank valve!

If the pipes etc are all still connected it doesn't matter as any gas released will just go along the pipe to the regulator in the engine bay. But! if you've disconnected any pipe from the tank and you activate the solenoid by applying a 12v to it - it WILL fill your face with -100?c pressurised vapour! so just make sure.

Also, if you find that it is the tank solenoid that's faulty, you should find that this is quite easy to remove - usually the coil housing is secured to the valve by a single small nut on the end: it should just slide off after this.

There are at least 2 solenoids: one on the tank as you know, one at the other end of the 6mm gas supply to the regulator/vapouriser at the engine and often a 3rd solenoid right next to the vapo one with a filter housing attached to it.

Both these valves are wired in parallel and should close/open simultaneously. If the engine stalls, both should close.

It's not impossible that your tank solenoid is faulty but I'd tend to want to check that it's getting 12v when you switch on the ignition (or select the LPG mode on the dash switch depending on what the car has) - just use a test lamp or multimeter.

One thing you can check is that gas has come through the tank valve by switching it on for a few seconds then off. Ignition off and then loosen the gas supply pipe to the vapouriser to see if there's an amount of gas held in the pipe. If these isn't then the tank valve did not open. If there is then obviously it did and if it doesn't start then the fault must be at the regulator or after (e.g gas injectors or mixer)

It's also worth checking the filter (if fitted) as this was blocked on mine any was difficult to start.

To check the filter, wind in the tank manual shut off again, begin to loosen the nut on the side of the filter housing - gas will leak out of a maximum of 5 seconds - wait till it stops before unwinding the nut fully. Remove nut, remove circular side panel, and pull out the filter. It should be clean and dry but might be full of weird red powder. if so, just clean it in white spirit or replace with a new one. When replacing the circular side panel to the filter housing ensure that the mating surfaces are SPOTLESS! as a spec of dust between them can cause a leak, tighten up the nut, check all the gas pipe connections there are still nipped up, loosen the manual shut off on the tank valve and switch on the ignition to prime. Give it a go for starting.

Sorry went on a bit there but hope it helps.

[aerodynamica]

Also! please don't attempt to empty the tank or manually fill it - this can be troublesome and you need special equipment that costs more than a tank of gas to do it!

Incidentally, where is the tank located on a Xantia? in the boot or where the spare wheel would be?

[bxman]

You should be able to change the coil on the solenoid valve without doing anything to the tank.
It slides off; it will be a nut or a cir-clip that holds it on.
No need to disturb anything else. The liquid gas cannot escape unless the coil moves the plunger that is within the tube that the coil mounts over and that will not happen without a current flowing through the coil if it has gone open circuit you will need it rewound or replaced .
I have in the past seen adverts from a specialist repairer on ebay but not there to-day.
If you can get an identical valve you can just swap the coil over.
good luck
Patrick

1.8 LPG xantia in green

[Sid_the_Squid]

Thanks for the info.
I have found 3 solonids, one in the tank, which is either stuck or the electric side dead, one on the filter in the engine bay, and one on the vaporiser/reducer itself, the two engin bay ones do switch simultaneously, and I can test them by applying a current clearly hearning a click from each. Applying a current to the tank valve I hear nothing.
I definately left all the pipes connected when testing the valves, I also took apart the filter to check for blockage, it was clear.

The tank is a full toroidal tank, mounted where the spare wheel would be, it appears to have a single 'control block' where both the in and out pipes are connected, as well as 4 wires, two large wires for the valve, two much smaller ones I assume for the level sender.
This is what the tank assembly looks like http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... ink:top:en I belive the solonoid is the black part, on the top is a plastic dome, probably covering a nut, if its possible to simply remove this coil would prehapse this do as a replacement?http://www.lpg-kits.com/image/vaporizers/vsgicoil.jpg

Thanks
Maybe its not so bad after all

[rmunns]

I've just seen this posting and I'm astonished that it's allowed for the tank and system to be installed by any old odd job man.

I only got involved in a car with LPG when I moved over here to France.

Here t is absolutely verboten to do anything with LPG (other than to fill up the tank!) unless you are a registered qualified engineer with the relevant specialty. You get a certificate and this has to be kept up-to-date. I'm surprised that you don't seem to need certificates in UK.

I'm even more amazed at the comment:

Explosions are pretty unlikely because the pressure in the cylinder would eject the gas before any ignition source could reach inside.

[xantia_v6]

The converse seems to apply to domestic gas.
In the UK, I am not allowed to install a new gas hob without paying a Corgi registered engineer
In France, I got a pamphlet though the letter box, from the local gas company, with instructions on how to install a gas hob

LPG in its pressurised state is a safe fuel (as safe as petrol), it is only when a volume of it gets mixed with air in an enclosed space that it becomes dangerous.

[Sid_the_Squid]

Seems LPG is still fairly unregulated here, anyone can fit it to their cars, with lots of DIY kits available, some LPG fitters will issue you a certificate of safety (for a small fee) after inspection, however most insurance companies dont care if you don’t have this certificate.
From some storeys I have heard even supposedly qualified registered fitters are sometimes cowboys.
Probably the most shocking things is my car has a certificate, yes the cowboy fitted lpg system is apparently safety approved. Well it works without leaks.
Interesting to me is France being stricter on health and safety than the uk? I though they usually took a rather relaxed attitude to such things usually, or is that a erroneous culture stereotype

[bxman]

Not wanting to be "pedantic"
The coil is not in the tank,
It is mounted within the center of the doughnut or on a chest on the outside of the doughnut in which case it could possibly be 4 individual units.
in, out, pressure relief and contents level.

If it is a combined valve and the coil will , I suspect, be smaller than the ones shown in the jpg. I think those are probably from an individual solenoid valve. (WRONG sorry never checked source out before opening mouth)

http://www.tinleytech.co.uk/acatalog/tt-shop.html

Is a good start , I found that they are exceptionally helpful.

It would be an idea to first find out which manufacturer made your
multi-valve, their name will be on the casting itself.

[HDI]

I've installed 2 LPG sytems to cars and it's pretty straightforward. The most difficult bits are finding a place for the tank and mounting it , well , thats if it's done properly and not just thrown in as I have seen it done many times !! Having said this , I wouldn't like to fit a system to a very recent ECU riddled car with clever injection !!