Fuel pump not working (I think)

[vindauga]

A little background; engine wouldn't fully start in spring. Would cough and sputter and then die. Would fire up when adding fuel to the air intake and then die. Bail on the manual pump was hanging free. Lots of help from the forum; bad fuel, dirt, carb rebuild. Drained tank; lots of crap. Rebuilt carb (probably 1st time in 40 yrs). Cleaned tank, rebuilt carb, installed new filter for dirt and water. Sucked fresh fuel from tank to just upstream of the sediment bowl (also cleaned).
Now engine won't start. Fuel pump bail seems to be pumping but I'm not getting anything through.

HELP! THANKS

[JOHN COOKSON]

Well, there is one way to find out if the fuel pump is working. Isolate it. Run clean fuel from an auxiliary tank right to the fuel pump, bypassing the boat's fuel system, and prime the line. Then disconnect the line to the carb from the fuel pump.Once you can demonstrate that the pump is pumping you can add segments of the boat's fuel system solving flow problems as you work along it.
Did you blow air back into the tank and listen for bubbles in the tank?
Did you check for spark? Easy to do. Pull a lead off a spark plug, put a screwdriver in it and see if you can jump an arc to the spark plug while you turn the engine.

TRUE GRIT

[hanleyclifford]

The recommendation has become almost routine that a fuel pressure gauge be plumbed in right at the carb. For a little up front cost and bother you gain constant capability to monitor the system. McMaster Carr is your friend here. Maybe someday this gauge will be in the Moyer Catalogue.

[vindauga]

Well, there is one way to find out if the fuel pump is working. Isolate it. Run clean fuel from an auxiliary tank right to the fuel pump, bypassing the boat's fuel system, and prime the line. Then disconnect the line to the carb from the fuel pump.Once you can demonstrate that the pump is pumping you can add segments of the boat's fuel system solving flow problems as you work along it.
Did you blow air back into the tank and listen for bubbles in the tank?
Did you check for spark? Easy to do. Pull a lead off a spark plug, put a screwdriver in it and see if you can jump an arc to the spark plug while you turn the engine.

TRUE GRIT

Engine will run when adding fuel directly to the carb. Pump was working before I took the carb off and drained fuel from everything. Fuel flows from tank through filter to the sediment bowl. Manually ran pump with discharge line to carb disconnected. Pump sounds like it is sucking but I am not getting any fuel out. Is there a way to prime the pump?

[JOHN COOKSON]

Engine will run when adding fuel directly to the carb. Pump was working before I took the carb off and drained fuel from everything. Fuel flows from tank through filter to the sediment bowl. Manually ran pump with discharge line to carb disconnected. Pump sounds like it is sucking but I am not getting any fuel out. Is there a way to prime the pump?

Are you sure there is not a blockage somewhere in the boat's fuel system?
To prime hold the hose to the pump upright with a oil adsorb pad in your hand and pour gas down it from a can that you have pinched into a spout.
I know MMI sells repair parts for mechanical fuel pumps. I have an electronic pump on my A4 and don't have any experience with mechanical fuel pumps. The mechanical pumper boyz will be along soon.

TRUE GRIT

[sastanley]

vindauga,

How long did you actuate the bail on the pump?? If you've cleaned out the fuel system, it may take a few minutes of pumping to get the fuel system/pump primed...especially if you are pulling thru a large water separating filter now..it has to fill that sucker up too. Oh wait, nevermind on some of that...I see you pre-primed the system to the sediment bowl.

Also, if the push rod for the fuel pump is in the wrong spot on the cam, the bail won't move the diaphragm inside the pump...you should be able to feel this though, because if you are moving the diaphragm you will also be working against the little springs/check valves inside..which won't pump fuel if they were assembled incorrectly..

Did you take the fuel pump apart? Make sure the sediment bowl gasket is sealing correctly too!

edit - +1 on the pressure gauge..I am using the Mr. Gasket 1561...my ONLY gripe about this inexpensive gauge is the plastic lens...I wish it was glass, because the plastic distorts/melts/fogs when you spill fuel on it..

[ndutton]

The recommendation has become almost routine that a fuel pressure gauge be plumbed in right at the carb. For a little up front cost and bother you gain constant capability to monitor the system. McMaster Carr is your friend here. Maybe someday this gauge will be in the Moyer Catalogue.

Y'know . . . . . . . the EWDS includes fuel pressure monitoring with a visual and audible alarm (aka Playboy alarm*) if the fuel pressure drops below the trip point.

*Playboy alarm - term sometimes used for a proximity alarm for ship board radar operators who, due to boredom, may be otherwise occupied and not as vigilant as they should be. Sometimes called a comic book alarm as well.

[hanleyclifford]

Mais non,

surely there are no playboys here.

[vindauga]

[QUOTE=sastanley;99529]vindauga,

How long did you actuate the bail on the pump?? If you've cleaned out the fuel system, it may take a few minutes of pumping to get the fuel system/pump primed...especially if you are pulling thru a large water separating filter now..it has to fill that sucker up too. Oh wait, nevermind on some of that...I see you pre-primed the system to the sediment bowl.

Also, if the push rod for the fuel pump is in the wrong spot on the cam, the bail won't move the diaphragm inside the pump...you should be able to feel this though, because if you are moving the diaphragm you will also be working against the little springs/check valves inside..which won't pump fuel if they were assembled incorrectly..

Did you take the fuel pump apart? Make sure the sediment bowl gasket is sealing correctly too!

Thanks all. Found that the sediment bowl was vapor locked. Unscrewed the retaining nut until the bowl was just free and then opened up the valve until fuel just started to spill out. Retightened the nut and it started right up.