Engine starts, runs a few seconds and quits

[JOHN COOKSON]

Have we determined there is no issue on the intake side of the fuel pump? Any restriction, clog or air leak there can produce the same symptom. I suggest trying to pump from one bucket to another eliminating the boat's fuel system from the test. If you have the same poor volume, the pump is the problem. If the volume is much improved, the boat's fuel system is the problem.

Divide and conquer.
This is the first thing I would do.

TRUE GRIT

[Neuse River Sailor]

I'm getting certain that it is the fuel pump

I have tried pumping from one container to another, bypassing the fuel system - that's when I got the ounce in three minutes - so that's clear that the pump is not delivering. Everything upstream of the pump is clear, I have added a squeeze ball so I can pressurize the system, and gas pours out of the intake hose when I pump it up. But once the hose is back on the pump, little or nothing comes out of the outlet.

My A4 guru who is well known and liked on this board told me to check out a thread about a stuck ball joint on a facet, and that sounds to me like what may be happening. My issue is that the position of the facet has made it impossible for me to remove the pump or get to the hex nut on the bottom that would let me remove the bottom and clear the ball joint. I just might be able to get a ratcheting box wrench on the nut, if I can determine the right size I will go out and buy one.

Joe_db, your point on the fuel pressure gauge is well taken. From earlier posts, I was looking for an "inline" gauge, but in fact do you mean a gauge on a t-fitting cut into the line between the facet and the carb? Nobody in this small town has any kind of cheap inline gauge, just rather expensive, large gauges that require a t-fitting. For this project, I already know what the output pressure of the facet is - approaching zero.

If I cannot get the bottom off the facet to clear the ball valve, the next step is to buy a new facet and mount it in an accessible place. I'll leave that for another post, if after searching the site I can't find information as to the proper location for a remote pump.

Thanks all for you help and encouragement.

[joe_db]

Joe, can you explain the vacuum gauge as it relates to the A4. I'm not clear where or what we should be measuring.
Thanks

If you hook it up between the fuel pump and filter, it will tell you if there is a restriction in the filter or the tank. If you hook it up between the filter and the tank, it will tell you if there is a restriction in the tank.

[ndutton]

I have tried pumping from one container to another, bypassing the fuel system - that's when I got the ounce in three minutes - so that's clear that the pump is not delivering.

It's time to replace the pump . . . .

[Neuse River Sailor]

It was the ball valve...

After struggling with it for a while, I got the bottom cap off the facet, cleaned out the trash, worked the ball joint against the spring for a minute, hosed it out with carb cleaner and then after another lesser struggle got the cap back on. The engine started easily and I ran it for about 20 minutes in the slip against the spring lines at about 1700 rpms. Once it cools I will go back over all the hoses and clamps one more time and tomorrow maybe I'll go sailing.

And yes, after seeing what came out of the bottom of the pump, I'd say it's time for a new one. I'll order one this weekend and bring it down next time I visit the boat.

For anyone else who has to get the cap off a facet without actually being able to see it, the knob on mine took a 7/8th inch box end.

Thanks all for the instructions and encouragement.

[ndutton]

And yes, after seeing what came out of the bottom of the pump, I'd say it's time for a new one

Good on ya . . . . if the little ball valve is full of krap it's a certainty the entire pump is too. Now, where did the krap come from? It didn't create itself inside the pump, had to come from somewhere (hint: tank). You don't want to subject the new pump to the same swill as the old one. You've solved the symptom, not necessarily the cause.

[roadnsky]

If you do decide to replace the pump, this would be an excellent time to consider mounting it on a bulkhead or someplace it is easier to get to.
If you do mount it on a bulkhead, be aware you'll need to run a ground to the mount of the pump. (See pic)

Also attached is a pic of the inside of the pump showing the filter and ball.

[Neuse River Sailor]

Mount

Thanks for the picture of the external mount, that is exactly what I have in mind doing.

[Jim Booth]

Great picture Jerry. This sure would improve access to stuff on that side of the engine as well as access to the fuel system parts. Maybe I'll do this before I add the O2 sensor. 😊

[roadnsky]

Thanks Jim.
I'm very blessed to have great access to all areas of the engine on my vessel.
Even so, I like having key components as easily reachable as possible.
As we like to say on this forum, "If it's easier to do, you're more likely to do it."