So I put a 1993 Dakota motor into my 1957 Dodge pickup. It is now running sort of! It will start and run a few seconds and then the engine starts sounding like it is slowing down and then it will die. It will not start again unless it sits for a few minutes It is a modded wiring harness done like the info I found here on the board. I have plenty of fuel pressure and a good spark at all times. Any Ideas?? Thanks moparts!!!