The engine stop device is a vacuum powered bellows in the aft part of
the injection pump. This little bellows wears out and gets oil logged.
Suggest you look at the aft end of the injection pump for a brown??
plastic vacuum line attached to a silver dollar size & shape device and
detach the vacuum line therefrom. If there's any lube oil in the vacuum
line the "shut down device" (bellows) is holed and must be replaced. You
can temporarily plug that vacuum line and use the car. But one must then
stop the engine manually by pressing the STOP lever on the engine's
throttle linkage.

If you want to replace the shut down device yourself be forewarned that
its not hard to do but IS tricky in that one needs to hook the end of
the bellows onto the end of the fuel rack (which it pulls to OFF when
one turns the key to OFF.)

Hope this helps you get underway.

Here's how the stop thingy works: when vacuum is applied to it
it pulls a rubber diaphragm inside which causes a lever to pull
a rod inside the injection pump which cuts the flow of fuel.

When the thingy fails it gets a hole in the rubber and all the suck
in the world won't make that lever move. That is, when it fails
you con't turn the engine off.

It's really really really unlikely it's failed stuck in the off position
which would require vacuum to be asserted, well, pretty much forever.

I take it the car has sat awhile? Not uncommon and you have two choices:
1) crank and crank and crank forever till you fluch the gum and crud out or
pull it to 35 mph and shove it into drive and it'll start. The latter
is what I've seen usually dont and I've never seen one that failed to
start this way.