S80 bifuel - now refuses to run on LPG
 

Hi, I am new to this forum and apologise if my problem is common and well known.
I bought this 2004 high mileage S80 automatic in February, it has run fine up until now on both petrol and LPG, apart from an intermitent report that the antiskid device needs servicing (any advice on this gladly received).

Last weekend I drove 300 mile to Cornwall, may have run the LPG a little low, when it decided to stop switching over to LPG. I have tried several times to switch it over manually but there is a total loss of fuel and hence power when I do. Runs fine on petrol. I did get a brief indication of things to come when it first refused, but a stop turn off and start again was successful just once, and a few strange change up or change down messages. But now no sign of LPG life at all :(

Any ideas or pointers please. I am hoping to be pointed to an economical way out of the problem, I am a reasonable mechanic prepared to undertake most things, so happy to follow a sound direction.

Is the car a factory-fit or a conversion?

Jack

Yes Jack an original factory fitted bi fuel model

Mike

Hi Mike

You'll realise from other posts on here that Volvo factory bi-fuels have a bit of a mixed reputation. Trouble is that main dealers don't often see them, and most non-franchised garages won't touch LPG. I believe it's fair to say that conversions are a bit easier to sort than factory-fits.

You may need to track down an independent LPG specialist.

Sounds like fuel ain't getting through (sorry to state the obvious!). You say that this started when the tank was allowed to run low.

The things that spring to mind are the valves, the filter or the LPG distributor / stepper motor.

I think that I'd be tempted to suggest finding an LPG specialist local to you and ask them to have a look initially.

Cheers

Jack

There is a brass elbow which takes the liquid gas into the evaporator , it's just after the solenoid valve which cuts the flow , all mounted on a bracket under the air filter , Take off the valve and unscrew the elbow from the evaporator . There is a spring loaded valve on the end which can stick , it should move freely when pressed with a finger , if sticking clean up with some "scotchbrite" or similar .. this is the most likelt cause considering the mileage and your symptom.
its best to exhaust the lpg line before you disconnect any pipes , but if it wont run on LPG may be difficult in your case so expect a small hiss of gas when you undo the pipe to the front solenoid cut off valve .. it wont last long ..

Thanks Jack - finally I get to have a look at it
 

The weekend is here, Saturday duties done, - I have not been completely idle about it I have purchased a set of spare gaskets and 'o' rings from http://lpg-kits.org.uk/shop/repair-k...-/prod_14.html

I have downloaded a number of pdf files showing the way to strip down the Necam components http://www.elpege.cz/pdf/manual-koltec-repase.pdf

So having decided to investigate your solution I am embarassed to find that I have no tool with which to undo the 4 segment clips which appear to hold the air filter in place? Any useful suggestions will be welcomed!

Meanwhile my wife - for it is her car has started to make comments on the cost of running it on petrol.

Hi Clan, thanks for the suggestion, I finally managed to remove the evaporator, remove the elbow and clean the spring loaded valve as you suggested. There were no apparent problems with the spring or the brass slide, I cleaned them as you suggested and have put it back together and on the car - sadly it has not affected the problem at all.

There was no evidence of any residual gas pressure in the gas lines so I am wondering if there is a solenoid valve somewhere which is U/S or has a wiring/signal problem. Can you tell me where on the vehicle they are to be found. I also put a spare fuse in the Bifuel fuse position which jhas also made no difference.

It is also the case that the problem had occurred a couple of times before but cleared itself when the vehicle was next started.

Any help/further ideas welcomed

It was certainly worth checking that valve , but if there was no gas pressure when you undid the pipe to the solenoid valve then look towards the tank . There is a second solenoid shut off valve on the tank , if you give it a tap with a spanner it may free , A new solenoid would be required if this is the case .
The LPG system isnt complicated , no gas = either a stuck soleniod or no current to the soleniod .( Or an empty tank! )
When the engine changes over to LPG you should hear a positive click in the boot area as the solenoid opens... or closes when you select petrol .

Thanks very much for the follow up Clan, is the solenoid valve accessible from within the boot or from underneath the car?

The solenoid is on the right side of the main LPG tank once you take the large tank protection plate off . The two supplimentary tanks share this main shut off valve .