Corky, cold starting the Lycoming IO-360 in my plane (1967 Beech
Musketeer) calls for mixture full rich. The boost pump is only operated
momentarily to assure that it's in working order. So I'm guessing you have
a Continental?

In any case, by running the pump until you have pressure squirts quite a
bit of fuel into the intakes just before the intake valves. In effect
flooding the engine. For most all engines, carbureted or injected, flooded
starts require mixture at cutoff. So now you crank until the engine lights
off on the fuel that is now in the intakes. Once running, enrichen the
mixture to keep it running. This is one way to start an injected engine
without a separate primer. Very primative compared to modern auto engines.
But That's what we have to deal with to get into the air!

Best regards,

Steve Robertson
N4732J

wrote:

I thought I understood the fuel injection process, but now I'm not so
sure.

When you cold start an IO-360, you are supposed to run the auxiliary
fuel pump with the mixture control knob pushed in until you see a rise
in fuel pressure, then shut off the pump and pull the mixture contol
knob back to shut off, and start the engine, pushing the mixture to
full rich when the engine starts.

How does the mixture control shut off the fuel? What does it control?
If the mixture is at idle cutoff, why does the engine start?

Another question, why do you start the engine with the mixture at idle
cutoff anyway? Why not start with the mixture at full rich?

Thanks, Corky Scott