V70 BiFuel - will not run on LPG
 

Hello, I've just bought a 2002 V70 BiFuel, which will not run on LPG at all...

It's a high mileage car (253K) but came with a year's MOT. It started immediately from cold, runs smoothly, sounds good.

I promptly drove it from Burnley to London, nae bother, so I'm liking it very much, 'cos I always wanted a Volvo estate :regular_smile:

However, even if the car is fully warm, and I'm on the motorway, when I press the button to switch from petrol to LPG, the indicator light flashes for a few seconds, then all the power dies and the car slows. Only way to continue is to press the switch again, which returns it to petrol.

I've read up on this, and whilst it sounds likely that the stepper motor is at fault, is it possible that another fault can cause this also?

I plan to keep the V70 for many years; I bought it knowing I'll have to spend some money to get it running properly :regular_smile:

So as not to drip feed; I should mention that when filling it with petrol, it leaks massively from somewhere between the filler tube and the top of the petrol tank :eek: It drips down from above the o/s rear suspension, and I think I can see the fuel pipe up there. I'll be fixing this soonest, and I can't see how it has anything to do with the LPG problem, but thought I'd mention it.

If anyone has any thoughts; I'd love to hear them, thank you :regular_smile:

Highly likely to be the stepper. Read my thread.

https://www.volvoforums.org.uk/showthread.php?t=280332

Still not got the LPG bit running!

She's now been to three London LPG specialists - none of whom could get the LPG side to run at all!

But recently, when parking her in a field (nose down) at a very very steep angle, when I restarted her after 5hrs, she spluttered then ran on LPG for the first time ever. Coughed and popped, smelled really bad, would not rev above 2000rpm...but she was running on LPG. I switched back to petrol manually - just to get her home.

Drove her a few miles next day on petrol, she stayed running on petrol. Then the next day, after one mile, she suddenly auto-switched over to LPG and I drove 20 mile across London with no problems - and she was definitely running on LPG. First time ever on LPG and no hesitance or spluttering.

The next day, she was back to petrol only and would stall after the autoswitch to LPG, so I'd manually switch back to petrol.

I love this car, she's really great, my first ovlov, and I really really want to get her to run properly.

Does anyone have any suggestions to find this very weird fault...?

Check the codes! Could be lambda playing up. I stripped the whole LPG system recently in my Bifuel twice recently. All hoses new, filters etc. I stripped my distributor cleaned and changed all parts exept stepper motor because mine is fine. I cleaned and resealed my non-oem evaporator! When I gave up I read the codes and it turned up that first lamda sometimes playing. I borrowed a lambda from another car and it runed like a dream for a week. Now need to buy one.
Is your car runs alright on petrol? I mean in the morning if it starts alright? A quick test can be done. You need to put your vacuum line from evaporator in to the water if bubbles come up - evaporator needs changing its seals. But you need to run on LPG for that test.

Buy some STP injector cleaner and pour it down the LPG line to engine. Start the car and try to turn it to lpg. It will stall immediately on switch over. Leave it overnight. In the morning turn it to LPG, it may stall a couple of times and a lot of smoke will fly from exhaust.

LPG definitely will need servicing. It is not hard and can be done DIY.

If there is still neck distributer you may wish at least to clean the inlet valve on the high pressure side. Beware of the liquid lpg escaping. When you will undo inlet pipe there will be a spring with some rubber and crap. That crap does not belong there and need to be cleaned.

If in unlucky event you still experience problems when running on LPG it is highly likely that you will need a new stepper motor that is volvo part only and cost like a whole car from dealers. CNGBifuel can possibly hook you up with some second hand unit that he used to rebuild a while ago and possibly still doing that.

There is multiple reasons for LPG not functioning OK and it is really hard to advise anything. I strongly advise to get yourself familiar with LPG systems and how they work as it can save you big money. Don't be afraid of LPG it won't explode suddenly unlike petrol. It is absolutely safe to work on the car outside and usually requires only basic knowledge of health and safety.

I wonder what exactly those LPG specialists has been doing to it.

Good Luck

P.S. Worth checking electromagnetic valves both front and rear before starting to do anything else.

2002 V40 LPG bifuel issue
 

My V40 runs perfectly well on start up, will auto switch to LPG once warm enough but shortly after driving fine on lpg it will switch back to Unleaded despite having plenty of lpg in the tank. Pressing the button to turn off lpg and then switiching back to lpg usually gives a little judder as the change happens, the lpg indicator shows for a split second then off again back to unleaded.
If I turn the ignition off and back on whilst coatsing or stop the car turn ot off and start again, it will then switch to lpg either automatically or via using the switch.

My mechanic at the start of the month whilst doing my MOT said there is a cable dangling down from a damaged senor on my exhaust near the cat and Lambda sensor. Now he seemed to think this was some sort of temperature sensor for the LPG system.

Russki you mentioned having an issue with the first Lambda senor? Can you please tell me more info about Lambda senors, how many, their location and any other sensor that may be in that similar location. As it is frustrating that my car will not continuously run on lpg!

Many thanks for any info