Six pot fires up slowly

[crankedup]

My 1928 vintage Vauxhall 20/60 is new to me and I have spent last few weeks doing minor sort outs to it. Have now got the engine to run on its six pots but starting up from cold is still tricky. It takes an number of key turns for engine to fire up and when it doe's it runs only on four pots. Then another cylinder chimes in and finally the sixth, this takes about an minute or so for things to smooth out to sixpots. Juggling with the manual choke seems very sensitive to engine running or not, I am used to manual chokes as I have owned an number of old cars previously. Any ideas as to why the engine will not fire up cleanly on the six cylinders please?

[rev-erend]

Two things to try - retard ignition timing by says 2 degrees ...

So from 8 degrees to 6 degrees.

See if its better.

Option 2 - richer startup mixture as fuel drops out of air suspension when the engine is cold.

[crankedup]

Thanks Rev-erand I shall give it an go.