2003 Chaparral 230 SSI 350 MAG

[lipscomb11]

I have Mercruiser 350. The problem I'm having is it doesn't start sometimes- when turning the key, I get no fuel pump prime or audible tone. Then it will randomly fire right up, when it does that I get the tone and fuel pump. It has new plugs, wires, distributor cap/ rotor, batteries, alternator, Ignition, and crankshaft sensor. I still has the same intermittent problems. I bought the cam shaft sensor that goes under the Distributor cap/ rotor, but when I went to replace, the sensor wasn't plugged in and I'm unable to find a harness back there for it to plug into, is that normal?

SN OM621398

 

[Fun Times]

Yes Mercruiser didn’t start using the Cam sensor until 2005 or 06 year model.

It seems you’re losing 12 volt ignition power that would wake up the ECM or something isn’t right on one of the relays on engine side by ECM… Or ECM isn’t sending out its signal to wake the system up for its 2 second prime.
Unfortunately all the parts changed wouldn’t really affect the wake up signal at first key up.

 

[lipscomb11]

Yes Mercruiser didn’t start using the Cam sensor until 2005 or 06 year model.

It seems you’re losing 12 volt ignition power that would wake up the ECM or something isn’t right on one of the relays on engine side by ECM… Or ECM isn’t sending out its signal to wake the system up for its 2 second prime.
Unfortunately all the parts changed wouldn’t really affect the wake up signal at first key up.

Thanks, also sometimes after cranking over and over, once I stop turning the key. I'll get the tone and fuel pump, I fires right up... not sure if that provides any additional input.

 

[Bondo]

Ayuh,..... Welcome Aboard,..... Could well be a bad ground,......

A good place to start, is at the battery,....
Remove, 'n clean to shiny metal Clean, both ends of both cables,.....