Hi

I have a standard 2.0L Pinto in a MK Indy kit car and I am getting one black dry sooty spark plug always number 3, running on a weber 32/36. I have tried

Swapping plugs

Swapping leads

Distributor round 180 deg.

removed PCV valve

Had block re-bored, skimmed, new pistons and rings, head skimmed, new valve guides, unleaded inserts, new valve oil seals

only using E5 petrol

Still No. 3 black and sooty mis-firing all the time

Any help appreciated ............ getting frustrated

John

Check valve clearances

Check compression on number three

Check dizzy cap and rotor arm

If you're running E5 set ignition timing to standard 4 star (original), not retarded for unleaded

1 hour ago, DaveT70 said:

Check valve clearances

Check compression on number three

Check dizzy cap and rotor arm

If you're running E5 set ignition timing to standard 4 star (original), not retarded for unleaded

Thanks DaveT70

Checked valve clearances and compression both ok, Cap and rotor arm look okay but will swap out and advance the timing