Merc 350 Mag not starting

[dralst]

I have an 00 350 mag has been running great, but now wont start. Does anyone know if the fuel water seperator should be full when running/ starting?
It has power to the fuel pump, coil, new plugs and cap/rotor. Running out of ideas.
Fuel smells ok...

 

[GrindKore]

Re: Merc 350 Mag not starting

Does the engine turn over? Or is completely dead? If later I know this may sound silly, but check your MOB kill switch.

 

[dubs283]

Re: Merc 350 Mag not starting

this is efi??

yeah, the water separator should be plumb full when operating

do you hear the fuel pump run for a few seconds if you turn the key to the run position?? (not cranking)

have you checked for blockage in the tank?? (fuel pickup)

have you checked the fuel vent line??

pressure/vaccuum test the fuel pump??

 

[dralst]

Re: Merc 350 Mag not starting

Does the engine turn over? Or is completely dead? If later I know this may sound silly, but check your MOB kill switch.

Checked the kill switch, seems to be fine as the starting tones go off. Will check for th pick up by pushing gas back into the tank

 

[dralst]

Re: Merc 350 Mag not starting

this is efi??

yeah, the water separator should be plumb full when operating

do you hear the fuel pump run for a few seconds if you turn the key to the run position?? (not cranking)

have you checked for blockage in the tank?? (fuel pickup)

have you checked the fuel vent line?? will try...

pressure/vaccuum test the fuel pump??

need a gauge / I guess NAPA
pumps a bear to get to

 

[dralst]

Re: Merc 350 Mag not starting

Ok, I tested the tank this morning and the pick up was not clogged. The fuel rails had pressure, but at the fuel separator there was little pressure. The pump comes on, makes noise and I can feel vibration when it goes on for that 1st 2 seconds.
Is the fuel pump shot or is the regulator suspect?

 

[dralst]

Re: Merc 350 Mag not starting

Turns over, but no deviation on the cranking. Tested it and has low fuel pressure.

 

[Don S]

Re: Merc 350 Mag not starting

How low is the fuel pressure, and what is the serial number of your engine. Have you checked the pressure regulator? have you followed the troubleshooting in the OEM service manual or just testing your own way?

 

[dralst]

Re: Merc 350 Mag not starting

I did the checking per the manuel minus a preasure gauge and code checker. key to on and had thumb on inlet weak pressure. Verified down stream was clear, emptied ythe fuel filter bown and cranked to twice for 7 seconds ea. only half a bowl into the filter. Feel the vibration of the pump working and hear it aswell. Pulling the regulator in the morning to check the filter.

 

[fossill]

Re: Merc 350 Mag not starting

the ignition part of the system works?