I would look over the wiring to the distributor and the connections. The description that it starts hard but once started shuts off as soon as you put in gear sounds like the motion of the engine may be flexing a broken/loose wire and causing this. You might look at the wiring near the shift linkage and that area as well. Another test would be to get it started then see if moving the engine wiring slightly shuts it off.
Monday, October 12th, 2020 AT 11:28 AM