spuratic spark

I have a 1988 Ford bronco with 302
Truck will not start...
Cut upper radiator hose while driving, so I duck taped it and drove to store to get parts... fixed hose... bought antifreeze... truck was warm, so I started truck and added anti-freeze it only took 1/10 of the bottle... then I closed the hood and was getting in the truck when it stopped running!!!

Turned over fine but would not fire....
Purchased ether thinking fuel pump went out... sprayed in intake and truck sounded like it wanted to fire... it would pop a little...Someone told me that could be detonation..... I may have an ignition problem...

I replaced the coil, distributor cap, the rotor, plug wires, had ignition module tested(not really sure if they new what they were doing)!!!

I am now testing spark at the coil wire directly out of the coil and do not get spark until I let go of the key... then it sparks at the end... I am wondering if this could be the ignition module...

Thank you

Take a 12 volt test light make sure you have voltage at the coil positive with the key on. Then put the test light on the coil negative the light should blink when someone else is trying to start the car. If it doesn't blink replace the pickup in the distributor. A special tool is required.
http://www.amazon.com/ Search THE415
If the light lights check the module. Also check the ground wire for the computer.
Look in left kick panel passenger side.