The shut-off lever will stay in the horizontal position after shut-off until vacuum bleeds (so to speak) from the system. Could be hours. If you turn the key to ON/RUN, the lever should pop back to vertical.

When you have a starting problem, check the position of the shut-off lever. If it's stuck down while you're cranking, pull the hose off the shut-off vacuum actuator. If the lever jumps up, the problem is in the key switch. If the lever stays down, the problem is inside the IP.

Sixto
93 300SD