Another problem has arised guys.
The TR i have on LPG is starting to play up.

I changed the head on it (M7) to an (M4) , and it ran fine for nearly a month. Now its started to miss on accelration, and every now and then it will backfire when trying to accelrate.

Pulled the plugs out, and they were coated white, what does this indicate?

I changed the plugs with another set out of a running car, and there is a bit of a change, but not much.

Anyone know what would be causing this?

Cheers