ive got an 89 coupe 4 cylinder car and just did a 93 gt drivetrain swap. the quesion ive got is this im getting spark to the coil pack when i initially start the car but as soon as the key is in the run position it dies(no spark). now i need someone to tell me where i can get a power source at that gives power to the coil when the key is in the run position.  second i need help wiring the fuel pump because now i have two fuel relays one under the seat (original in the car ) other is under the hood on the engine harness which is the one i would like to use. now this is the problem i have no power to the fuel pump but im getting power everywhere else head lights, tailights, brake lights, gauges,etc. i need to know how to use the fuel relay under the hood on the engine harness. any help out there would be great thanks.

I've got some ideas. First power to your fuel pump........have you checked your fuel pump switch. Its located in the rear of your car. Take off the panels to get at it. Its a small black box with a white button on the top of the box. Reset it by just pushing. As of the spark problem i had the same problem with my stang but mine was a 86 4 cyl. I never figured it out but it kills me that i cant figure it out. I'll keep trying to help you out. I'm looking at wiring diagrams right now so i'll give you a holla if i find anything.  

It sounds like you didn't swap the wiring harness.  The best way to do a conversion like this is to swap EVERYTHING, that way you don't run into problems like this.  Without knowing what wiring has and hasn't been swapped, it's hard to give you advice.  So, I'd get the complete wiring harness and procede to install it.  Good luck.

i think 7 is on the right track. you most likely have to change the wiring harness that is located on the passenger side kick panel. this half of the harness has the computer on it. You need the v8 harness and computer. You should not have to change the whole harness just that half. if you have done this already i would take it to the mech. and have them look at it.