0M091282 = MERCRUISER 4.3L ALPHA EFI 2 PC Exhaust (MEFI 3 ECM)..., Here's your correct parts guide,
https://www.mercruiserparts.com/4-3l...62-v-6-0l61900
In here is your wiring diagram and ignition test sequence you'd want to follow along with...,
http://www.boatfix.com/merc/bullet/99/99_02.PDF
Does the tachometer seem to move while cranking over the engine?
Does the helm gauges show 12 volt power at key-up?
Have you removed, inspected/tested all the engine fuses at the engine side and reinserted them if good while checking for electrical corrosion to the wiring?
The safety lanyard kill switch at the shift control handle is for sure in the run position?
Be sure the mercruiser shift interrupt switch isn't affecting ignition operation such as a sticky shift cable for example at the engine shift cable side.
The gray wire at the rear of the tachometer ought to be removed for spark testing as a bad tachometer could prevent spark operation.
In theory with/should everything else was to be working correctly for proper power, grounds, etc., The sensor under the distributor cap is the starting point to get your fuel injector pulse width operational...Item number 6,
https://www.mercruiserparts.com/bam/.../31497/5388/50
