Having a few problems - Misfiring on LPG

[catch22]

Hello all,

I'm having a few running problems when running on LPG.

Now, this all started when I ran low on coolant due to a leak and the car started to run a little rough due to to vapourisor/gas temp.

After curing the leak and bleeding the system the car ran fine again but seems to have a little misfire at light loads around 3.5k rpm.

This misfire has got worse over the last couple of months and now running on LPG seems to be a no go.

The car runs fine on petrol (Impreza WRX).

The system in a BiGas SGIS with a double vapourisor.

The plugs leads are new.
The plugs are only 12k miles old and are gapped to 0.55mm
The LPG filters have been replaced a couple of weeks ago and were clean.

So what do I do to sort this out?

Can I clean the injectors and vapourisor somehow? I have read about soaking them with WD40 and then carb cleaner. Can the Bigas injectors be taken apart to do this or shall I leave them assembled.

One last point to mention was that I have lowered the vapourisor pressure from 1.45bar to 1.3 and even after a recal, the problem is now worse. Blockage?

Cheers for any help.

[catch22]

Ross,

The injectors are indeed the fat ones!!

The vapourisor is balanced before it hits the filters which were clean when cut open and replaced.

I'm thinking injectors here too.

We soldier on......

[junkcatcher]

Quote "The plugs are only 12k miles old"

12k miles = past sell by running date on LPG

New set of standard or irridium NGK's might work wonders.

Chances are the spark plugs got over heated durring your cooling system problems and the insulation of the nose of the plug inside the combustion chamber has brocken down.
LPG puts a lot higher demands on the plugs and ht system than petrol.