Volvo Owners Club Forum - View Single Post - S40 02 1.8 Bi-fuel LPG issues

capt jack · Feb 28th, 2011, 19:03

Hmm. Don't assume all is well with the plugs, even if they are only 6 months old.

My LPG-converted V70 doesn't like anything but Bosch or better still Denso single point copper cored spark plugs. Luckily these are just about the cheapest available.

The symptoms that a plug change is due (anything between 5,000 and 15,000 miles) are an intermittent misfire, under load at just under 3000 rpm.

The misfire goes away under any other circumstances.

Sounds a bit similar to your problem!

Before doing anything else I'd suggest whipping out the plugs, and if they are the fancy multi-point type, bin them and fit nice cheap standard Denso ones for around £1.50 each.

Petrol is far more forgiving of minor ignition hiccups than is LPG, and in any event LPG chews up spark plugs at a greater rate than does petrol.

If that doesn't work then's the time to start thinking about more complicated and involved issues.

Cheers

Jack

PS: My guess is that your factory fit system will have a filter, and will require a pressure check. Certainly after market systems do! Rather than Volvo, have a meander through the LPGA web pages and see if there's an LPG specialist near you. They'll probably have more experience of LPG Volvos than all the main dealers combined!

Jack

Feb 28th, 2011, 19:03	#2
capt jack VOC Member Last Online: Apr 20th, 2024 18:56 Join Date: Jun 2006 Location: Selby, North Yorkshire	Hmm. Don't assume all is well with the plugs, even if they are only 6 months old. My LPG-converted V70 doesn't like anything but Bosch or better still Denso single point copper cored spark plugs. Luckily these are just about the cheapest available. The symptoms that a plug change is due (anything between 5,000 and 15,000 miles) are an intermittent misfire, under load at just under 3000 rpm. The misfire goes away under any other circumstances. Sounds a bit similar to your problem! Before doing anything else I'd suggest whipping out the plugs, and if they are the fancy multi-point type, bin them and fit nice cheap standard Denso ones for around £1.50 each. Petrol is far more forgiving of minor ignition hiccups than is LPG, and in any event LPG chews up spark plugs at a greater rate than does petrol. If that doesn't work then's the time to start thinking about more complicated and involved issues. Cheers Jack PS: My guess is that your factory fit system will have a filter, and will require a pressure check. Certainly after market systems do! Rather than Volvo, have a meander through the LPGA web pages and see if there's an LPG specialist near you. They'll probably have more experience of LPG Volvos than all the main dealers combined! Jack Last edited by capt jack; Feb 28th, 2011 at 19:05.