One plug sparks on SR

Hey guys, only one of my spark plugs works right now. The one closest to the firewall works, all the other three don’t spark. I swapped out the coils and they’re all fine. I checked the grounds on the back of the motor, took out the screw, sanded the area and put them back on, still nothing.

Not sure as to why the first three aren’t firing. Everything is plugged in correctly, looks all good. Can I somehow ground them individually and see if that works?

Cam sensor.

Were they working before? I had it where all but one wasnt sparking…there was a break somewhere in the wiring for the one coil from the ecu…

Yeah they were all working before perfectly before the motor was pulled.

Last night the car fired up for a few seconds then died out.

When I first checked for spark it was really weak except for cyl 4. Now only #4 fires.

How would the CAS affect the strength of the spark??