Ok i just swapped the motor in a 2000 neon, but i cant get it to start, the starter is fine, but i can't manually crank it, i know it isnt seized because when i was attaching the pressure plate to the engine i had to turn it and it cranked then, i've never done anything to a auto tranny before, when i put the tranny on the new engine, i had it on its side and lifted the tranny on top and lowered it on to it, the weight of the tranny didn't make it sit flush there was a 10mm or so gap but when i tighten all the tranny bolts it got rid of the gap, does that sound right? i cant think why the engine wont crank it must have something to do with the tranny right.

 

I can tell you for starters, you should not have had to crank the bolts down to get rid of a large gap. Was the torque converter spinning 100% freely and backed completely into the transmission housing up to the moment you bolted the transmission to the engine? My guess is it was not considering the outcome. That can cause the situation you are in.

 

Update?

 

bump^