In article ,
G.R. Patterson III wrote:

You're hitting the primer before cranking? That loads the induction system with
raw gas, basically flooding the engine. When you wait a bit, some of that gas
vaporizes and the engine starts more easily.

I noticed that some time after I got my Comanche I had trouble starting
it. I finally realized that I had just gotten too fast at the start
procedure after doing it so many times. In particular the IO-540 seems
to benefit from at least a 2-3 second count with the fuel pump on after
you go to idle cutoff and a few seconds for the fuel to evaporate after
priming. The "symptoms" of doing the procedure too fast were basically
like the original poster described -- nothing doing on the first crank.

--
Ben Jackson

http://www.ben.com/