EFI to replace Edelbrock carb

It's the early on that has frustrated most users. When you don't know what the problem is, how can you fix it. I had an ECU go bad in an EFI unit. How do you trouble shoot something like that. Had to send unit back to Mfr. to have it fixed. It only quit working when hot, ran ok when cold. Luckily the 2 times I got stuck with EFI, I was not too far from home so flatbed charge wasn't too bad.