To trouble shoot improper shutdown on Precision Airmotive/Bendix style FI:
Disconnect the hose that goes form the fuel injection servo (or throttle body if you prefer that terminology) to the flow divider(or manifold valve if you prefer calling it that). Place mixture control in idle cutoff and confirm it is hitting the stop, at the fuel injection servo. Turn on boost pump and observe any fuel leakage at the hose you disconnected. It should be no more then a drip every second or so. No steady steam, no matter how small. If just a drip, drip, drip or less, the problem is likely the flow divider. If more the drip, drip, drip, the problem is the mixture plates in the servo or the mixture control rigging.
Also, if you should have a manual auxiliary primer system , installed for some reason, you should also disconnect that, and run and shut down the engine, to make sure it isn?t allowing fuel to the engine during the shut down operation and causing the run on situation.
Adjusting the idle mixture way lean, as you have done, may help with the shut down, if there is something else wrong, but it will also make the engine hesitate, cough or maybe even quit on aggressive throttle application. Not the best situation. Generally speaking, an idle mixture either a bit rich or lean at idle shouldn't have any effect on shut down capabilities of the engine, if everything else is working as it's supposed to.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."
