[Car Nut]

Dave,

I double checked the Ford Service manual, it clarifies "When fuel injected engines are turned off, fuel in the fuel lines remains pressurized for long periods of time to provide quick start ups."

As I remember, you are using the Ford SEFI systems, probably from a Mustang and you have a stock regulator providing for no adjustment. The regulator mounts on the fuel rail and has a rubber diaphram.

If you don't have any other leaks, I would suspect the fuel regulator, the diaphram could be leaking internally or the seat is worn out allow fuel to return to the tank or into the intake manifold (if the diaphram is leaking). Anyway, its the cheapest to replace.

A fuel injector could be pissing into the cylinder after it is shut off. Check your plugs immediately after shutting the key off and pressure drops.

The fuel pump itself could be worn and is leaking back preventing fuel pressure to be maintained when it is not running.

If none of the above are it, then its Don's fault as he is full of leaks.