Just a guess, and I'm certainly no mechanic, but it seems you're getting a combustible mix to the cylinders only when enriching the combustibility with your starter spray. Between that and the long storage, I'm thinking injectors that need either cleaning or replacement. FWIW--good luck!

__________________
Craig Bethune

'97 SL500, 40th anniversary edition

'04 Olds Bravada (SWMBO's)
'06 Lexus ES330
'89 560SL (sold)


SL--Anything else is just a Mercedes.
(Kudos to whoever said it first)