Cold LPG Problem

[Danielson]

Recently had my 221 powered ute converted to LPG using Impco L converter and 300 mixer mounted direct onto a weber throttle body. Overall it's great and cost to run is heaps cheaper 240 miles for $37.00 or 59 litres so far. The problem is when cold it missfires quite a lot as well as on light acceleration and under light load, although idle is ok. Once well warmed up say 10 minutes the problem is gone. I have a piece of stainless flywire that I installed under the throttle body when it was on petrol which I am not sure has anything to do with it. Any other ideas ?? It's kind of like a petrol motor when its way too rich but I can't seem to tune it out ?
Thanks Daniel

 

[addo]

Did you recurve the distributor at all? Sounds like the advance could be excessive for a cold motor.

 

[Danielson]

Thanks for the thought, distributor is an XF unit that hasn't been recurved, I have tried it at various positions with no change other than once going below about 14 deg initial the idle drops a lot and so does power.
Cheers Dan

 

[aussie7mains]

Check your spark plug gaps gas needs higher energy to light the fire and your old coil might not be capable of this, so close the gaps down to 0.5mm.
You might be getting freezing in your convertor, how youve plumbed up your heating water cct and you thermostat might not be right.
A7M

 

[Danielson]

Great and thanks for the help, a smaller 25 thou plug gap cured the problem.
Thanks Again Dan