Black plugs

Just done an ignition service on the 3.5 Efi, freed off the centrifugal advance mechanism, replaced dizzy cap and rotor arm (Lucas) set the static advance to 10 degrees and changed the plugs.

The plugs were all very sooty. The vast majority of the time, the engine runs lpg. Can this cause sooty plugs if set up rich??

The air flow meter barn door is cracked and doesnt move smoothly so I imagine thats causing it to richen up on petrol.

Kieran

lpg does not cause sooty plugs , unless you have switched to petrol and lpg is still coming thru. By what you say its a petrol prob esp if flapper is not working properly as that adj the mixture by virtue of airflow sencing .