496 mag won't start sometimes?????

[talbert450r]

I have a 2007 Mercruiser 496 MAG and sometimes when I go to start the motor the starter engages and the motor won't start. This does not happen all the time but when it does it will crank and every once in a while you can hear it try to start but it won't. Sometimes it will start fine and other times it may take several attempts approx 15-20. This started happening after I hit a pretty big wake and after the boat landed it immediatly died and I have had this problem ever since.

 

[talbert450r]

Re: 496 mag won't start sometimes?????

The motor always starts when I first put it in the water.

 

[Don S]

Re: 496 mag won't start sometimes?????

An intermittent problem is the hardest type problem to nail down. and with an MPI engine, it gets evern harder.
A wiggle test on all connectors on the engine (even that one for the Crank Position Sensor under the vibration dampner that you can't see) while the engine is running is one thing you can try (Carefully)
Visually checking every connection for corrosion or bent pins is another.
Might also do some fuel pressure checks when it's warm, and get the engine checked for any trouble codes.
Being as it's a 2007, call the dealer. It's a warrenty issue.

 

[talbert450r]

Re: 496 mag won't start sometimes?????

Thanks for your response I will check the connectors, anybody else have any input. All the dealers around here are booked for a while so I hope to fix it myself if its something simple.

Does anyone know if there is some sort of inertia safety sensor like on a car to shut off fuel in case of accident?