I posted before but I have more info now, and exhausted the search button :P. S4 turbo engine into an s5 vert. Using the s4 ecu/wiring harness.

All pinouts have proper volt/ohm readings at the ecu with ignition on but the vehicle will not start. using a spare CAS when i spin the cas i get good spark while cranking but not with the cas thats in the vehicle. If i swap the cas out with the toher one its the same scenario. spinning the extra gets spark. if i take off both leading and lay them on the fender they get a good spark but if i try grounding them to the block its poor. so i added another ground strap from engine -> battery.

i OHMd out the cas signal wires at the ecu and get 155.4 and 154.4 which is the same as direct plug from the ecu. The only thing i have yet to try is to put in a fresh battery (its on the charger now) to see if possibly that could be having an issue as i have no idea on the compression of the engine. it feels like there are strong pulses when i remove the spark plugs (no dead apex seals) but i have no idea how long the engine has been sitting before it got to me.