No spark or fuel

[El Supracabras]

I'd prefer to keep this on the forum for the benefit of others who may run into your problem.
What have you checked so far? Did connecting the grounds change anything? Do you have a multimeter? I need answers and actual measurements. Its impossible to start this car via a keyboard and screen without some important information. Here fill this out:
Stored codes:
Battery voltage:
Voltage at main relay:
Voltage at EFI fuse:
Voltage at EACH ecu power supply:
Ohm reading of ecu ground to chassis.
Condition of ALL grounds related to the ecu including coil pack ground wire:
Position of the timing marks on all of the gears and the cam sensor:
Fuel pressure:
When you crank the engine with a test lamp between the battery positive terminal and the ground wire of any injector clip does it flash? Does it stay on? Nothing at all?:

There's your homework, the wiring diagrams and procedures are all over the internet and this forum if you need them as well as the tsrm, report back with these answers and we can go from there. Don't stress and don't skip any steps, it sounds like you're putting a lot of money into it. Take your time, be thorough in measuring everything and you will no doubt get it running again.