Hi Espos4, sorrry but I forgot to mention that the no start is with my port motor. Starboard starts up with no problem. Buddy of mine said it could be the pick up coil. Just wondering about that
The ignition sensor is located in the distributor under the rotor. About $100.
And, on the efi engines it is a common fail item. Mercruiser actually came out with a new and improved sensor.
I do need to correct myself though. A bad ignition sensor will inhibit the fuel injectors.
I have the 4.3l mercruiser 190hp and just went through a no start issue. I didn't have anything but a multimeter which I used to rule out my battery, solenoid and coil. I replaced a corroded cap and rotor but it was the ignition switch that fixed it. Good luck to you.