1994 Ford Aerostar engine won't turn completely over

Electrical problem
1994 Ford Aerostar 6 cyl All Wheel Drive Automatic

1994 ford aerostar van fuel pump went out, parked for 3 months, replaced fuel pump, now engine won't turn over to start, took starter out & replaced it, replaced battery but van still will not turn over. Took starter off & replaced it turned flywheel manually but it stops, will not turn all the way and make complete cycle it wouldn't go anymore. Help please on how to get the engine to crank up motor will not turn on completely it stops 3/4 of the way. (Engine will not crank over for van to start, engine will only turn 3/4 of the way & engine will stop, hard to turn even manually)