1998 Mercruiser 5.7 EFI fuel leak

[Tunabass]

I have not dug into it to much other than looking at the fuel filter and shut off. After fishing today. I pulled the plug after the day and there was a strong smell of gas in the bilge water. Any likely places I should start my search on an EFI? I've done some searching on here but can't find anything that for an EFI. Thank you.

 

[alldodge]

Howdy

I have a thought but would like to know your engine serial number to make sure you have what I'm thinking about

 

[Tunabass]

OLO12923

I don't know if those are Os or zeros

 

[alldodge]

The O's are zeros, but you probably have O-rings (item 27) are leaking. Remove the cover off the cool fuel module and place a paper towel under where the fuel line connects. Run for a bit and see it this is where the fuel is coming from.

BW where is the bilge water coming from

 

[Tunabass]

Thank you. I'll try that. The water is probably coming from the livewell and going down the rod holders which are right next to it (in the transom). Not the best design. If not there then probably a leaky belo I guess

 

[Tunabass]

How do I remove the cover. Is it just a single Phillips head screw in the center of the cover. It's virtually impossible to get to on my boat. Thank you

Edit. Never mind the cover was missing. Running it now with diapers underneath to see if there's fuel leaking. The bottom of the whole box smells like fuel after I run my hand over it so I expect that's the issue. To replace that stuff looks like I'll have to pull the manifold and maybe the alternator. Update to follow after running

 

[alldodge]

Merc didn't do anyone any favors mounting it there for sure. The cover is held on with two clips which are on the top and bottom in the middle.

http://www.mercruiserparts.com/bam/subassembly/31884/2704/80

 

[Tunabass]

I let it run for maybe 10 minutes with absorbent pads under neath it and it is soaked with fuel. Primarily on the aft end as far as I can tell. How much of a pain in the ass is it to change that out after I pull the manifold? Thank you.

 

[alldodge]

It will be a pain.
The bracket that holds the entire cool fuel is bolted to the motor mount. There are two nuts one on each side. Remove the hoses. The fuel lines need to be removed from the pump, and the cooler. The pump end is threaded, the cooler end has a socket head screw pin (item 9) which is removed before the line can be pulled out.

You can just remove the pump and cooler and leave the housing under the motor. Remove all the hoses and lines, then remove the restraining plate (item 13) by removing the two nuts (item 14) which hold it in position.


http://www.mercruiserparts.com/bam/subassembly/31884/2704/80

 

[Tunabass]

Thank you. I'm going to tackle it on Monday. Today I pulled the manifold to get more room and see what was going on. It was a pretty significant leak of almost two drops per second. Not cool! Tight space that hopefully my mechanic buddies can get creative with. I'll post the results. Looks like it is one of four O rings at the elbow that connects the fuel pump to the fuel cooler. Item 4 and 5 above.

 

[Tunabass]

Cracked fuel pump. Replaced it and the cooler as you can't buy just the pump anymore. Problem solved.

 

[alldodge]

Glad your up and running.

Note: You can find just the pump its just Merc doesn't sell them that way. Just search for 861156A1

 

[Tunabass]

Thanks Alldodge. Good to know. At least I won't need to mess with it for a while now. What a pain!! Thanks for guiding me in the right direction!