1990 Vert FC Cranks but won't start ?
 

I picked a FC Vert a couple months back and it was running perfectly fine until one day it decided not start. I started addressing things on the vehicle changed the primary injectors, fuel pump, leading coil, spark plugs and wires and new battery and that work for that day in my garage, I moved it out thinking it was fixed but then after it just would not start at all unless I sprayed starter fluid it will run. Checked my compression and it all checked out, Now I know I have spark and fuel because my plugs do get wet with fuel and I have tested my coils and wires. I figured perhaps the CAS was bad so replaced that still no improvement. My last recent attempt today was to swap out my ECU which it had a N352 and picked up a N353 and still no start. One thing I do find strange is that my fuel pump primes with the stock N352 that came with the car now if I swap it out and install the N353 it cranks but the fuel pump will not prime. All fuses are fine my grounds seem to be okay and relays get voltage??? At this point I'am kind of almost giving up but I just don't want to let go so I'am trying everything. Any tips- Advice will be great appreciated to anyone that reads this.

Welcome to the board. :)

Have you gone through the deflooding procedure? Dry the plugs, cut off all fuel to it and see if it tries to start then.

Hey diabolical thanks for reaching out, you know I totally have and have like 4 sets of Trailing and Leading plugs just incase the get covered to much in fuel. Its real strange how this all happened after I swapped my primary injectors. I have a relay coming in the mail which I hope works, the relay is the black relay next to the driver strut thats is grounded. I have read that relay can some issues so I will try that. Also I have a question? So I swapped my thermostat sensor behind the water pump housing now what I noticed is that on that harness/wiring there is a black plastic connector hanging loose which I can't figure where it goes? Any ideas? This is a S5 13b N/A just to fill you in on those details.