S40 02 1.8 Bi-fuel LPG issues

[tainted]

Hi All,

I'd appriciate a bit of advice if anyone can help me out?

I've got a factory fitted 2002 S40 bi-fuel, it's been faultless in the five years I've had it until recently. It is an ex-fleet car fully dealer serviced until my ownership where I picked up the baton.

Anyway, the matter at hand....

It runs fine on petrol, when on LPG it feels like it's mis-firing between 2.2-2.5k revs, although it's more of a judder for a few seconds (in much the same way if you'd put it into too high a gear too early) and it goes away.

Typically it only happens when under load or heavy acceleration in 4th or 5th, if gently accelerated it isn't apparent at all. Otherwise it is noticeable if in second and doing a U turn on a roundabout

Initially I suspected dodgy coils, so I replaced both those and the associated HT leads to no avail. The plugs are also only six months old from the last service I did.

So, having spoken to my local Volvo dealer about it their suggestion was the gas distributor. I have two choices here:

1, Have the gas distributor tested and checked for £47, any minor problems would be fixed inclusive of this price.

2, Replace the gas distributor, a cost of £470. If I did this then the above would be free.

Now, while I've serviced my car yearly (I only do 8-9k a year) I've never changed or touched anything to do with the LPG system. I'm also unsure if the LPG system has any filters or if option 1 is anything that I could do myself.

I'm sure I'm not the only one but with budget cuts, mortgage, high maintence wife (looks over shoulder) and two kids anything I can do myself will be preferrable.

Any suggestions or advice will be greatly apprieciated.

Thanks!