350 mag mpi sn ow396614 cool gen 3 no start

[fish4striper]

Hi,
Hope you guys can help. Both engines start easy and run very good. Then one day last week port eng just stalls as its close to temperature. Started back up but died again. Let it cool down, now wont start at all. Shot starting fluid in throttle and starts up so I figured it was no fuel. Checked pressure at fuel rail, none. Chased around, fuses ok, tried wiggling connections, replaced fuel pump relay and now I get power down to fuel pumps. I tried starting but wouldn't start. Fuel pump runs for 2 secs then stops when the key is turned. Don't get any pressure to the fuel rail. I tried turn key off and forward it pump runs every time for 2 secs. Several times but never get any pressure at the rail.
Is the secondary pump dead and not sending fuel to the rail? Not sure how the two pumps work. If the 1st pumps shuts off after 2 seconds, what sends power to the secondary pump to feed the rail constantly?
Any help would be appreciated. Got to get this running soon to winterize. I'm in the northeast.
Thanks, Jeff

 

[Bondo]

Ayuh,..... Welcome Aboard,........ Change the fuel filter, 'n examine the contents of the old one,....

 

[alldodge]

Welcome

Don't get any pressure to the fuel rail.

You have the Merc fuel MODULE which has a low and high pressure pumps

If your "sure" the fuel pump is running and have zero pressure at the rail, then remove the fuel filter (item 26) and look inside to see if cavity is fuel gas.

If filter is dry or close to dry then need to look toward the tank to see if something is restricted or the low pressure pump is unable to suck fuel from the tank.

If filter is close to full then look at high pressure pump and fuel pressure regulator

 

[fish4striper]

Thanks guys. Yes been looking at forums and videos about the cool generation 3 module. With key switched on, I hear pump run for a cpl seconds then stops. I'll pull the filter tomorrow and see if fuel is present or not. If it is full of fuel, I'll pull the module off and take it home to try pulling it apart. I guess depending on corrsion, breaking screws, will determine whether I buy the whole module or try a pump and/or regulator or cover.

 

[fish4striper]

Pulled filter and no fuel in that cavity. Filter fell apart as I tried to pull it out. Bottom filter looks dark color on the bottom of it. I guess I need to see if I can pull fuel from the tank first before I look at the module.

 

[alldodge]

The tank will have a antisiphon valve with rubber fuel line connected to it

 

[fish4striper]

I was gonna buy an external fuel pump and see if I can get gas from the tank. Looking at my tanks, I see some electronic valves. Do you know how they work?

 

[alldodge]

They are manual valves so you can shut off a fuel supply. They are in the correct position for use, but could be clogged. The external pump will let you know if fuel can be pulled from tank

 

[fish4striper]

Well couldn’t find an external fuel pump so got a piece of fuel line and used my dinghy tank. Turned key, pump whined back and forth a few times, still no fuel pressure at the rail. Pulled new fuel filter and no fuel in there. Pulled module, only broke one bolt and it’s a mess inside per attached pic, paint peeling, etc. Also broke the end of the fuel hose that goes up to the rail trying to get it out. Where do you guys suggest buying a gen 3 module and hose?
Thanks, Jeff

 

[fish4striper]

Actually not sure if I broke the end of the hose. It was only a small flare. This is a pic of the receptacle in the cover. Not sure if it should be like this or if there’s a piece of the hose in there. Anyone have a pic of the end of the hose? Boats an hour away, can’t show a pic of the end.

 

[alldodge]

That needs a full rebuild if not replacement.

I have not taken one of them apart but looking at manual 40 (cool fuel) it shows seals on the ends of the pumps, so right now I'm guessing nothing is broke.

 

[fish4striper]

That needs a full rebuild if not replacement.

I have not taken one of them apart but looking at manual 40 (cool fuel) it shows seals on the ends of the pumps, so right now I'm guessing nothing is broke.

I'm going to buy a new module. From looking at someone's video, I did bust the end of the hose. How do you look up the parts diagram on these online places, boats.net or mercruiserparts.com. My serial no is 0W396614 but I can't seem to find that group of serial nos. What is my motor called in the place to pick a parts diagram? See attached pics. I think the hose is 8M2005177(line Cooler to Rail) based on this but I'm not sure I'm in the right serial category.

 

[alldodge]

Its best to copy the link in the upper bar then past it in the link button. Posting picks of your laptop is not very readable
Always use the serial number to look up parts

Fuel Module
Item 35 is the hose

 

[alldodge]

The new pump assembly is 8M0047215 which I'm seeing almost $1800

 

[fish4striper]

The new pump assembly is 8M0047215 which I'm seeing almost $1800

Yeah, ouch. Thanks for your help.

 

[fish4striper]

She runs! New module did it. Thanks for your help guys!!

 

[alldodge]

Good deal and thanks for update