2002 S60 Won't switch to LPG

[nige0568]

I've searched the forums and can't find an answer to this. I've recently acquired a very nice 2002 S60 with factory fitted Necam LPG. When I first got it it was fine switched over and ran perfectly on LPG, it then started to refuse to switch to LPG, I tested the solenoids and they were fine, I checked the filters they were fine, I disconnected the brass elbow beneath the air filter box and stripped and cleaned but still no joy, I then disconnected the battery for a few hours and upon reconnecting it it then switched over to LPG and ran fine again for a few days then it started again failing to switch over, so I disconnected the battery again for a few hours then reconnected, it then switched to LPG but almost immediately switched back to petrol, now it completely refuses to switch to LPG, again I've tested the solenoids etc, I've put a multi meter across the solenoid wires and there is no 12v signal. I've checked the fuses etc and they seem fine, sorry for the lengthy post but has anybody got any ideas what to look for to rectify it.

[capt jack]

Volvo factory fit LPG sadly is notoriously poor. The usual failure is the regulator - the bit that re-vapourises the LPG when it comes through from the tank. New Volvo ones are the thick end of £800 I think, with no guarantee that it'll be any better than the old one. It is possible I think to upgrade the system with an aftermarket system.

Cheers

Jack

[nige0568]

Cheers jack, that is what I was worried about, I'm going to an Indy lpg installer this afternoon after work, I'll see how much to change the front end of the system, cheers nige

[capt jack]

Yes, I think that it's just about you're only serious option if you want to continue using LPG.

Do shop around though as over the years I've heard various different outcomes.

Certainly the firm who did my conversion were able to source a replacement - Autogas 2000 in Thirsk, North Yorks. But it's almost a year since I sold that car so things may have changed.

Good luck any way

Cheers

Jack

[spokoluzik]

You can buy rebuild set for necam system. They are about 50ish quid or so. Then after repair you need to set right pressures. Pretty common problem is also stepper motor and isn't cheap( about £250).
They very simple systems and if you keep it well maintained it will last for long time.
Now every company uses conversions with separate ecu and most of settings are being done using computer. Thats why is so difficult to find person who know how to use gauge and set everything correctly without ready to use program. I'll try to find some instructions how to repair vaporizer and set pressures. Below link to repair kit. In worst case you'll have to spend about £300ish incl stepper motor. Still cheaper than converting existing conversion...
http://www.ebay.co.uk/itm/KOLTEC-VG3...item3cdf6eb581

[reggit]

Do you have access to vida/dice? If you have a faulty stepper motor it may have thrown a code, mine did when I had an S60 bi-fuel. A new motor at around £300 (Autogas2000 in thirst) had it perfoming faultlessly. Prior to changing it, the car would either not switch to gas, or stall without warning at random times.

[nige0568]

I don't have access to vida, yesterday I fired both solenoids from a 12v supply and both operated allowing the gas to flow but it looks like that they are not getting the signal from the ecu, I tried 2 Indy installers neither would look at it but I was quoted £500 for a complete front end replacement, I might just save the pennies for that

[reggit]

Check your coolant level - I can't remember now if the necam vaporiser on the S60 has a temperature sensor, have a look and if it does change it.

As you know they won't switch to LPG until it reaches a certain temperature. If it's not getting the 'I am warm enough' message, it will never switch.

It may also be worth reseating the ECU's in case you've got a slightly dodgy connection.

[nige0568]

The coolant level is fine, the vapouriser has not got a seperate coolant sensor, the only one I can see is to the right of the thermostat, I disconnected that momentarily and it changed the revs slightly so I guess that's working, I'll try reseating the ecu, is it the main one on the bulkhead because there is something that resembles an ecu on the left in front of the power steering fluid reservoir

[reggit]

Not sure what's on the bulkhead - with ECU's live in a black plastic box on drivers side inner wing just behind the headlight (mine had 2 in there, I think one was the engine and the other the gearbox ECU) - would advise you disconnect the battery before having a look though. LPG reverts to permanently off after a battery disconnect, you need to push the 'petrol' switch with engine running to reactivate it.

Meant to ask - what's the light doing on the 'petrol' switch? Is it constantly on, or flashing?