Car cranking, no start

Engine completely redone. Car ran very well for over a year but would stall while driving and after few minutes start again. Gradually got worse, intermittent spark and fuel relays would not kick in to switch on fuel pump. Sent ecu in and they had to replace board as ground track burnt.
Car ran again and started same problems again after a while. Sent ECU in again and they said nothing was wrong with it.
Next thing, coil pack packed in. Tested wires to coil pack and distributor/CDI unit and got permanent ground from ECU on signal wire. To get car running again so I could get to work, added a diode to distributor signal wire so it could send signal to ecu and stop permanent ground from ECU. Cut coil pack signal wire and added it to distributor wire. Car started but did not run well as idle control and other sensors were getting same permanent ground on signal wire. Sent ECU in again, and they said it was fine and were very irritated saying I should not have a permanent ground on signal wire. I am stumped and car back to not starting. Disconnected all plugs, lights, radio and getting same result. Been looking for a short and nothing. Any suggestions?

Oh, and distributor and coil pack has been replaced.