Fuel flow issues

[Bold Rascal]

Okay, so my recently serviced A4 ran really well for the first 3-4 hours of it's new life but this weekend it failed and I limped home on my auxilary outboard.

The engine was running just fine and then died. Tried restarting and she fired right up but died just as quick. No fuel?

When I could I pulled the fuel line coming off the discharge end of the still "clicking" electric fuel pump and tried pumping some fuel into a small coffee container. Sputter, dribble and very poor to 0 flow. I bypassed the fuel filters and still got no flow. I blew air back thru the fuel line to the tank and heard it bubbling, My vent line is also clear.

I replaced the fuel pump with a spare that I keep on board, Same result, very poor to 0 flow.

I'm wonderring if I have a pin hole air leak in my fuel pick up tube? It is over 30 years old..

Any advice?

Mike

[Marian Claire]

Do you have a squeeze bulb in the fuel line? Dan S/V Marian Claire

[edwardc]

When I could I pulled the fuel line coming off the discharge end of the still "clicking" electric fuel pump and tried pumping some fuel into a small coffee container. Sputter, dribble and very poor to 0 flow.

I had this exact same behavior about a year and a half ago. Turned out something (alcohol?) had softened the seat of the ball check valve in the pump, causing the ball to stick to the seat. May also happen when the pump sits unused for a long time. The test/fix for this is simple.

With a container under it to catch the cup of gas that will come out, remove the bottom of the pump. It's a bayonet "twist-off", with a nut-shaped protrusion on the end for a socket wrench.

Remove the pump's internal strainer basket and set it aside.

With your fingertip, lightly press upward on the bottom of the now-exposed check-valve ball. It should actuate smoothly with little pressure. If it doesn't, apply a little more pressure untill it breaks free with a "click".

Reassemble and retest the flow.

Good luck!

[Marian Claire]

I have had the same experience as Ed describes. Was the spare pump new, with the factory oil, or was it used? I now store my used pumps after pumping MMO thru them in hopes that they will not stick. Dan S/V Marian Claire

[Bold Rascal]

No and it's not that kind of pump

Thanks for the trouble shooting info Ed however, the current fuel pump and spare are one of those cheapo non servicable sealed types, hence the spare. I do plan to purchase an INDIGO pump from the Moyer catalog eventually but wanted to rule out everything else before spending the money and still having the problem.

Thanks also for the fuel bulb question Dan. Nope, I don't have one. The engine has been started and run succesfully several times since I got it running again without hesitation or issue. I'm curious though, should I consider installing one?

The boat had been sitting on the hard for 6+ years with fuel in the tank. I did physically drain and remove the tank. Cleaned it and refilled with ethanol free mid grade gas this spring. The carb was cleaned and rebuilt this spring as well.

I know that a pump will draw air easier than it will a liquid.

The fuel tank had approx. 12-13 gallons of old fuel and water in it when I drained it. After thoroughly cleaning and re-installing the tank I put in 16 gallons of new fuel. Guess how much gas I currently have in the tank? approx 12-13 gallons. Just a coincidence?

I just have to wonder about this since the po replaced several components like distributor, coil, fuel filters and the fuel pump before he ultimately gave up on the motor.

[Dave Neptune]

Mike, try a separate tank with the same line if you can, an old OB tank or even a gas can if your careful. It does sound as if you and the PO have been looking for the same thing. A pinhole or a crack in a pick up line can ack just as you described, The fuel delivery is fine until the fuel level gets near the leak. My guess is that it is worse in calm water.

Dave Neptune

[Marian Claire]

Mike: No need to add a primer if you do not need one. Just something else to go bad. Post # 12 here will explain my question. http://www.moyermarine.com//forums/s...ead.php?t=4964 I know my "stuck ball" was on a Facet pump I assume that was true, from the description, for Ed. Dan S/V Marian Claire

[Marian Claire]

Was the cheapo pump like the 20$ variety from the Auto parts store? I used one once and it died after about 4 hrs of use but it did get me back to the marina. Dan S/V Marian Claire

[Bold Rascal]

Lol

It was $62.58 and has a full years warrenty, a fortune!

Thanks guys. If I get your drift, your suggesting bypassing as much of the fuel system as possible and to take an outboard style fuel pump/line directly from the tank or "other" source to the carb? Yet another systematic step in the process of elimination.

I'll try it tonight!

I'll also be draining the carb and checking the main jet.

Thanks again!

[Bold Rascal]

Runs fine on the bulb

I rigged a fuel tank with a hose and squeeze bulb directly to the carb and primed it. She started right up and ran great so long as I squeezed that bulb afew times every so often. Good throttle response and smooth idle.

Do I assume this would rule out a problem with the carb?

I didnt have time last night and the bugs were ferocious. This evenning I'll dump that 3 gallons into the main tank and hook everything back up to see how she responds.

[ILikeRust]

Do I assume this would rule out a problem with the carb?

Sure sounds like it.

[Marian Claire]

I would put the squeeze bulb in place of the fuel pump. Use your main tank, pick-up tube, filters etc. And test. Be careful not to over prime. You can force fuel past the float valve and flood the carb. Been there done that. Dan S/V Marian Claire

[Bold Rascal]

Fuel pick-up

Here's a pic of what the fuel pick up tube looked like the first time I saw it last March/April. Probably the first time it's seen daylight since originally being installed back in 73'.

The lower black section of the tube was emersed in old gas (at least 6 yrs).

The upper green section was exposed to the fumes and such. After cleaning the tube the lower section looked fine but that upper green section was fairly pitted.

I'm going to pull it this weekend and make up a new replacement. Even if it's not the culprit right now, I'll bet it would be eventually.

Thanks for the help guys!

[hanleyclifford]

Is that a small hole I see at the top of the tube?

[Bold Rascal]

It does look like it but:

I did a quickie soap bubble test on the pick up tube after I cleaned it, prior to re-installing it. It was'nt leaking then.

Anyone have any thoughts on a Polyethylene pick-up tube for gasoline?
It's supposed to be compatible.

My thinking was I could cut off the offending portion of the current tube (say it's 3/8" od), make an oversize slip joint out of the next larger size PE tubing and then re-insert the size smaller PE tube for the balance of the length. Matching ID's with OD's

Or? If the current tube is 3/8" od, conceivably I could find some 3/8" id PE hose and just sleeve it over the entire length of the existing. Either way I'd need some type of fuel proof sealant.

I did check around on the Moeller tank site but didn't see anything that looked like a direct replacement. What I did find was made out of PE.