1993 7.4L Gen V Fuel Pump Issue?

San_Diego_SeaRay

San_Diego_SeaRay

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Serial Number 0F009622

1) Can't get my engine started and decided to look for fuel pressure. I disconnected the fuel line from the pump and turned over the engine. No fuel comes out. Bad right? Can't be the anti-siphon valve preventing the pump from pumping?

2) Someone posted a few years ago how you can just buy the Carter(?) equivalent instead of Sierra or Mercruiser. Is that still possible? I know the correct Mercruiser part numbers are 818383T which was superseded by 861677T.

Thanks in advance! View attachment VID_20230313_174904309.mp4
 
San_Diego_SeaRay

San_Diego_SeaRay

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Fun Times said:
Do you happen to know if there's fuel in the fuel filter and it's full?
Click to expand...
The water separator? Yes, was full. Didn't take note of the in-line fuel filter in the fuel hose coming from the fuel tank. I *should* have looked. :(

Note that this engine hasn't run in over a year.
 
Fun Times

Fun Times

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Yes the Fuel/Water Separator filter...Then yes if truly full you ought to start to see fuel flowing out if everything was working correctly.

While it may or may not affect the fuel flow directly depending on issues, chances are the fitting where the tubbing is connected might be clogged as well which wouldn't let you know if the diaphragm is damaged inside.

The pump looks replaced at some point being the color it is.

Yes Carter is an option brand as well.

If possible, you could try adding an external fuel supply to see if it helps get the pump pumping and see if maybe there's an issue towards the tank.
 
San_Diego_SeaRay

San_Diego_SeaRay

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Fun Times said:
If possible, you could try adding an external fuel supply to see if it helps get the pump pumping and see if maybe there's an issue towards the tank.
Click to expand...

Hmmm. That's a good idea. I can buy one of those fuel primer bulbs and apply pressure my own pressure. Do you happen to know the size of the fuel hose that fits on to the barbed nipple on water separator inlet?

By the way, I painted the whole engine this color so it *could* be the original fuel pump. I really don't like black. 😁
 
Fun Times

Fun Times

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You'll want to confirm yours of course but typically I believe it to be 3/8".... Something like the following as for any "testing you'd like to try", https://www.walmart.com/ip/Hit-Upon-Marine-Outboard-Boat-Motor-Fuel-Gas-Hose-Line-Assembly-3-8-with-Primer-Bulb/296413419?wmlspartner=wlpa&selectedSellerId=18988&adid=22222222222399362871&wmlspartner=wmtlabs&wl0=e&wl1=o&wl2=c&wl3=74766932582378&wl4=pla-4578366467008933&wl5=&wl6=&wl7=&wl10=Walmart&wl11=Online&wl12=296413419_10000020145&wl14=marine outboard fuel line hose 3/8&veh=sem&msclkid=491d335b0f181e9bf831574b081f39c1

Note that most outboards are 5/16" so they can be harder too find size wise... Here's a bunch to scroll through if desired,​

Genuine Mercury Marine parts, large inventory, fast shipping. Fuel/Oil Tanks, Lines, Filter Kits and Corrosion - 1994 & Up

Genuine Mercury Marine, Mercruiser and Mercury Racing engines, parts, propellers. Authorized dealer with large inventory, great prices, fast shipping!
www.mercruiserparts.com www.mercruiserparts.com

 
04fxdwgi25

04fxdwgi25

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San_Diego_SeaRay said:
Serial Number 0F009622

1) Can't get my engine started and decided to look for fuel pressure. I disconnected the fuel line from the pump and turned over the engine. No fuel comes out. Bad right? Can't be the anti-siphon valve preventing the pump from pumping?

2) Someone posted a few years ago how you can just buy the Carter(?) equivalent instead of Sierra or Mercruiser. Is that still possible? I know the correct Mercruiser part numbers are 818383T which was superseded by 861677T.

Thanks in advance! View attachment 376322
Click to expand...
On the anti siphon valve being a possible problem, the answer is a definite yes. Had to replace one on a couple of boats before. To test, just pull it off and replace with a std fitting to see if problem goes away. If it does, just replace with a new valve.
 
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dubs283

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Scott06 said:
this is a mechanical pump driven off the raw water pump? In video Belt driving it is not moving when engine turns
Click to expand...
Agreed

The fuel pump is operated by a cam lobe on the water pump shaft. In the video the belt that turns the water pump is stationary when the engine is being turned over. Appears the belt isn't tight?

In any case, if the water pump isn't turning the fuel pump will not work. Anytime one replaces the water pump impeller/housing the gear oil in the water pump housing needs to be changed.

Can't say for sure but I do believe the water pump housing for that application is NLA
 
San_Diego_SeaRay

San_Diego_SeaRay

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Scott06 said:
this is a mechanical pump driven off the raw water pump? In video Belt driving it is not moving when engine turns
Click to expand...

1678801361738.png

Well now I feel real special. :)

I removed the belt so that I could "dry" run the engine for 30 seconds w/o ruining the impeller.

Thank you!
 
D

dubs283

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04fxdwgi25 said:
Actually, they are readily available. Std Bravo pump setup for older Bravos. Rebuild parts readily available, too.
Click to expand...
Yeah, was referring to the metal shaft housing not the plastic impeller kit

Looking on merc epc the metal shaft housing is still available, is expensive tho
 
04fxdwgi25

04fxdwgi25

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dubs283 said:
Yeah, was referring to the metal shaft housing not the plastic impeller kit

Looking on merc epc the metal shaft housing is still available, is expensive tho
Click to expand...
Yeah, I was talking about the drive housing. The plastic pump body on mine (and last 2 before it) went the way of the dodo by upgrading to the Hardin S/S pump body.

The drive housing will last almost forever, if you keep up the maintenance on it and replace seals and bearings when needed. Never had to completely replace one.
 
San_Diego_SeaRay

San_Diego_SeaRay

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04fxdwgi25 said:
Yeah, I was talking about the drive housing. The plastic pump body on mine (and last 2 before it) went the way of the dodo by upgrading to the Hardin S/S pump body.

The drive housing will last almost forever, if you keep up the maintenance on it and replace seals and bearings when needed. Never had to completely replace one.
Click to expand...

Yep. I rebuilt one a few years back using this helpful Youtube video. Bought the bearings off of Ebay.
 
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