LPG advice for a friend please!

[rawkyjnr]

Hi all,

My friend is running a Subaru Legacy GT, with LPG. It does suffer a few problems though..

Firstly, it can cut out when pulling up to traffic lights when cold.

Also, it has a mid-range misfire for certain.

I have connected up an OBD-II and it says that the knock sensor has "high input", is that the sensor that is at fault, or something (the LPG) is causing excessive pinking?

I must admit he hasn't had the LPG serviced for years, is this likely to be where the problems lie?

Cheers

[rswift]

Have the LPG serviced, and the LPG filters changed. Normally should be done annually/12k miles.

[shovelheadrob]

Assuming he has a proper multi point injection system, it normally piggy backs off the engines ECU, there is a correction factor in the software to compensate for the change in calorific value of LPG. This may need to be adjusted, or the whole system may need re-mapping, some have the ability to "learn" others have to be programmed. He will need to find a service centre that has the software to work with his system (same manufacturer) this can then be done in conjunction with a service. Sounds complcated, but just a matter of plugging in a laptop & adjusting as you drive. HTH

[maser_spyder]

Plugs, HT leads, sticky LPG valve, could be anything.

But if it's never been serviced, that's going to be the most likely cause. Gas is dirty, the filters and valves actually DO need cleaning every 12 months, and you can't get away with avoiding it!

[BadgerBill]

Don't want to be a keyboard mechanic, but when I was looking to gas our old outback there was a lot of teeth sucking, talk about a flash lube system and valve seat erosion. Hope it is fuel delivery/ignition related, but perhaps go to some log forums and look up common faults with subaru installations.

BB