Runs for a half then stalls and has no spark for a few hours afterwards

[bubbajoe234]

I have a 1999 Dodge Ram 1500. My dad and I replaced the old 5.9 magnum motor with the same motor from a '98 truck now the motor will run for a half hour then it will stall and when I try and restart it I will get no spark to the coil for a couple of hours afterwards. We tried a new ignition coil and that didn't help. Can i get any pointers?

 

[dodge dude94]

Replace your ASD relay and see what happens.

Might be getting hot for whatever reason and tripping.