1993 7.4L Gen V Fuel Pump Issue?

[San_Diego_SeaRay]

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 I know the correct Mercruiser part numbers are 818383T which was superseded by 861677T.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

 

[Fun Times]

Do you happen to know if there's fuel in the fuel filter and it's full?

 

[San_Diego_SeaRay]

Do you happen to know if there's fuel in the fuel filter and it's full?

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]

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]

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.

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]

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

 

[04fxdwgi25]

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

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.

 

[Scott06]

this is a mechanical pump driven off the raw water pump? In video Belt driving it is not moving when engine turns

 

[dubs283]

this is a mechanical pump driven off the raw water pump? In video Belt driving it is not moving when engine turns

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

 

[bman440440]

this is a mechanical pump driven off the raw water pump? In video Belt driving it is not moving when engine turns

Scott nailed it!!

 

[San_Diego_SeaRay]

this is a mechanical pump driven off the raw water pump? In video Belt driving it is not moving when engine turns

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!

 

[Scott06]

View attachment 376334

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!

We all have felt real special many times … you can probably fill the carb via the vent or dump gas down it to check if it runs

 

[04fxdwgi25]

this is a mechanical pump driven off the raw water pump? In video Belt driving it is not moving when engine turns

Now I see it, had to go to full screen to get the resolution.

We have all had those DOHHHH days.

 

[04fxdwgi25]

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

Actually, they are readily available. Std Bravo pump setup for older Bravos. Rebuild parts readily available, too.

 

[dubs283]

Actually, they are readily available. Std Bravo pump setup for older Bravos. Rebuild parts readily available, too.

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]

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

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]

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.

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