Merc 5.0 Bravo starts then dies

[h2oboarder]

Engine starts with key in start position and then dies when it moves to run. Engine runs stays running if you hotwire starter posts (purple-yellow) with main or if you run bypass directly into purple-yellow terminal. <br /><br />What is causing the engine to die without hotwiring the solenoid?<br /><br />The Merc is a 5.0 litre serial M030334, model#4m12025n1 standard rotation year 2000 motor. It is in a inboard skiboat. There is no lanyard stop that I know of.<br /><br />The boat runs fine when you jumper the purple-yellow wire with the main starter post. Fuel pump continues to run. Thought it was the ignition switch - but same problem after replacement. Tried replacing the starter solenoid but problem still exists. <br /><br />I read something about the ECM cutting out if the battery is bad/low or if the voltage regulator is bad. ???

 

[bunnybonker]

Re: Merc 5.0 Bravo starts then dies

hi, im an electrician, try checking for continuity of all cables (wires) from key switch, not knowing youre system or engine configuration, but somtimes engines when in normal opperation use a ballast resister to drop the voltage to the coil if you have one of these check you have a current from it when key is in run poss.

 

[tommays]

Re: Merc 5.0 Bravo starts then dies

you have and oil pressure sender for your guage and a oil pressure switch in the fuel pump circut that keeps the pump on when the motor is running<br /><br /><br />tommays

 

[h2oboarder]

Re: Merc 5.0 Bravo starts then dies

Thanks I'll start with those points.

 

[milkyway]

Re: Merc 5.0 Bravo starts then dies

I have 5.0 year 1998. I also have a purple and yellow that connects to the oil pressure sender. Must be a bad oil pressure switch where these 2 wires are connected to. The switch is about $25.