Volvo 2002 V70, 2.4 Bifuel CNG - Few problems.
 

Greetings, firstly wanted to say hello Just registered.
So, I got a V70 2.4 with factory built-in CNG installation, necam variant.
My main problem is that sometimes (more often nowadays) the engine switches off when running on CNG (on a petrol works just fine), by switching off I mean that it just dies completely. I have to stop the car, switch manually to petrol, turn the ignition off and on just to start it again.

I know that CNG overall is better than LPG but it's not popular in Poland, we got ver few gas station around the country (there is only one in my city), also I can't find a proper workshop to maintain my CNG installation, everyone refuses to touch it because it is factory built-in. So I decided to remove CNG from car and install LPG (station around every corner, cheaper than CNG, every kiddo can fix it etc).

If anybody made that kind of coversion I would like to know basically every detail (or just removing built-in CNG):

I assume, CNG is programmed in the main ECU, is there a possibility to reprogram ECU to make car think he is just an ordinary gasoline vehicle?
I read when you remove CNG components, there are tons of errors stored in the memory and ofc a check engine light on.
Also I would like to have a gasoline lvl indicator in the right place (instead of the CNG pressure/lvl), because at the moment current petrol level is displayed on the left LCD panel.
Like here http://media.clusterrepairsuk.co.uk/...79331_big.jpeg

Sorry for the long post and ... bad english

All I do when I remeove the factory fitted systems is pull the main parts out but leave the wiring and switch in place. Keep the switch in petrol position.

You can then fit a new system as normal,

In your case might be an idea to look for a good used factory fit LPG tank

This is one of the options but I was thinking about getting rid off all the CNG stuff and reprograming the ECU. Do you think this is possible?

I'm sure the ECU could be reprogrammed. Have a look for someone that does remapping or ECU cloning to do it

Yes but firstly I'm going to call my local authorized workshop, they are able to download data directly from sweden, they reprogrammed TCM in my car to fit new gearbox (2004). Yep I made a swap, AW50-50SN (2002) and AW50-51SN (2004) :) Also I got an ECU unit from donor car (same engine as mine but without CNG).

Can I have your old CNG parts? I suspect all it ever needed was a new stepper. You certainly describe the correct symptoms for this. I'll PM you.

Dear nonlin3,
I have the same priblem with my v70 CNG. The engine often switches off in CNG mode.
Have you found the problem, what could cause it?
Thank you

Yes. I found best solution. I've removed CNG and installed 5th gen LPG. Car runs flawlessly. There is no logical reason for keeping CNG in this car. Company who made it for volvo discontinued any support. You will not get new parts. Remove, install modern LPG. After removing CNG tanks (there are 3) there is plenty space for one huge LPG tank, I've got myself 90 litres.

Well there's a thing. I've just done the very opposite.

I found a factory Volvo BiFuel car with what might be 'the best solution' - it's factory system removed and a Zavoli LPG kit installed. It was pretty poor job that didn't work. I was going to put a 5th gen. system sourced from our very own 'classicswede', thus - if you like - its third system install.

I'm sure it would have been very good. Only, it came easier to put everything back to ex-factory standard.

That's not to say any other way is wrong, if it works that's the right way for you. In my case I could find no logical reason to stray from the factory fit Necam system, it works.

Good for You. At this point car made over 100 000 km with LPG instead of CNG, and I had to spend less than $100 to maintain it :) In Poland you have like: 10 CNG stations, some have operation hours like 8 am to 10 pm... How about LPG? More 6300 places to fill up you car. Basically every gas stations has a LPG.
1 liter CNG: $0.90
1 liter LPG: $0.50
Go figure, CNG is dead-end here in Poland.