FiTech EFI system

I'm having a weird issue with my power adder. All trouble shooting points back to the unit. Ran great for a week. Now it just cuts off for no reason. It's hard to crank afterwards too. Seems to be something with tach signal. I have an msd ignition. Took it out of the loop. It got worse with the unit running the ignition. I've tested about wire and ground. No luck. The car is simply undrivable right. The first week got me hooked. I want the efi. Not sure what to think now.