2003 Chaparral with 5.0 L MerCruiser MPI engines and Bravo II drives. Starboard Engine will not start at times and other times starts perfect. Either hot or cold same problem. Batteries are good. 2018 - New cap and rotors, OEM Merc ignition wires, fuel filters and IAC replaced in 2017. Engine runs great after starting but often will not start unless throttled. Has spark when not starting.

Need some help as my marine mechanic canít figure this out.
Checked with computer scanner and has no codes or error messages.

Engine serial number is OM342923.

Any help is appreciated.