could be an injector, coil, or the ignitor pack, the wiring to the ignitor pack, the wiring from the ignitor to the coil, the wiring to the injector, it even could be the cas.
start with, pulling the coil out of cylinder 1 and swapped it for say cylinder 2, if the problem moves to cylinder 2 then its the coil. if it stays on cylinder 1 then its something else.
then i'd checked the injector is getting its pulse, is it squirting fuel. if it is its probably the ignitor or cylinder 1's ignition wiring. if not then id check the cas out.