Motor runs fine then dies a few minutes after restart.

[EJORG]

I have had what appears to be a fuel pump problem. I have a relatively new Facet electric pump on an A4 that I have been running with almost no problems for more than 20 years with only careful regular maintenance. But at the end of last season anad again now, I am having some problems

When I first turn the key on, the pump runs fast and never slows down like my old pump did, presumably when the fuel line has enough pressure. it just keeps running fast

When the motor runs it seems to be fine. Very smooth, starts quickly, etc.
But if I shut off the motor and restart it, say after sailing for an hour, it often runs for a few minutes then dies. And clearly it sounds like there is no fuel getting to the carburetor. When I turn on the key and try a restart I hear the fuel pump behaving the same way - clicking rapidly and not slowing down. Sometimes it runs again for a while and sometimes I can't start it.

I have tried disconnecting the fuel line and turning the pump on, and indeed it is pumping fuel. I also know that the lines are not clogged. Could it simply be that its not pumping enough fuel and never pressurizing enough? Generally if I remove the hoses then reconnect them, the motor restarts, but tonight even that did not work, and I was left drifting in no wind.

I do not understand why it is less likely to run after running and then being shut off

I am thinking the best bet would simply be to swap out the fuel pump. I have another one somewhere - but I am just trying to figure out what is going on. Any ideas?

Thank you -

Erik Jorgensen, Portland Maine.

[edwardc]

I've had these same symptoms, and been left drifting in a channel without an engine too. Here's what I found.

The Facet pump has a ball-and-spring check valve in the lower part. Something, (I never determined what) causes the ball to become partially or fully stuck. With the carb hose end removed, there is fuel flow, but it's misleading, because there's almost no pressure or volume behind it.

So the pump is delivering little, or no fuel, and the engine is burning it faster than it is beeing delivered. In a short time, the float bowl becomes depleted and the engine stalls.

A quick "on the road" fix is to remove the bottom of the Facet pump (it has a bayonet type twist-off with a hexagonal boss for a socket wrench) and remove the strainer screen. The bottom of the check valve ball is then accessible with a fingertip. Pressing on it a few times should free it up. In my case, it came free with a palpable "click". Reassemble and the engine should start right up as soon as the float bowel refills.

But this is only a temporary fix. Once prone to sticking, it will stick again. DAMHIKT. The heat of running also seems to make the sticking more likely. The only permanant fix is to replace the pump.

I suspect some kind of contaminant in the fuel was the cause, but I never was able to identify it. Also, a fuel pressure gauge at the carb would have allowed me to identify the problem a lot sooner.

[ndutton]

Adding to Ed's first hand experience, if the pump delivered 20 years of reliable operation maybe it's time to retire it with a thank you for a job well done. I'm not concluding the pump is the problem but there comes a time when it has served its useful life and I suggest you're there.

[roadnsky]

I have a relatively new Facet electric pump on an A4 that I have been running with almost no problems for more than 20 years...

When I first turn the key on, the pump runs fast and never slows down like my old pump did...

Erik-
Welcome to the forum!

How old is the "new" Facet?
Is it the same model as the one it replaced?
Also, are you points/condenser or EI?

The attached pic is the inside of the Facet showing the screen and ball that Ed describes.
As he said, a fuel pressure gauge in-line would have answered a lot of your questions.

[ndutton]

I missed that Jerry and my comment reflected the misinterpretation.

This sounds like a case in need of an 'undo' button. The engine ran fine for 20 years, replaced the fuel pump and now it doesn't. Hmmm, OK, what's different now than the last time it ran well? Fuel pump.

[JOHN COOKSON]

Generally if I remove the hoses then reconnect them, the motor restarts, but tonight even that did not work, and I was left drifting in no wind.
Erik Jorgensen, Portland Maine.

Another welcome to the forum.
A side issue issue: When you remove the hoses how do you do it? If you just pull a rubber hose off a barb it can leave little bits of rubber loose inside the hose. These little bits of rubber can raise hell downstream.
Agree that is sounds as if the "new" pump is not working correctly.
That said when the pump is pumping rapidly is there any chance that fuel is not getting to the pump? Maybe when you sail crud is stirred up in the tank and the fuel is outlet tube is blocked. This can be tested with fuel directly to the pump from an auxiliary tank bypassing the filters.

TRUE GRIT

[Administrator]

Any chance it was plumbed backwards?

Bill

[ndutton]

Any chance it was plumbed backwards?

Anything's possible but in post #1 we have this information:

I have tried disconnecting the fuel line and turning the pump on and indeed it is pumping fuel.

I wouldn't expect that if the inlet and outlet were reversed.

[joe_db]

A general note - I would have given away my A4 for scrap by now without fuel pressure and vacuum gauges. Knowledge = Power

[HalcyonS]

The Facet pump has a ball-and-spring check valve in the lower part. Something, (I never determined what) causes the ball to become partially or fully stuck. With the carb hose end removed, there is fuel flow, but it's misleading, because there's almost no pressure or volume behind it.

...

A quick "on the road" fix is to remove the bottom of the Facet pump (it has a bayonet type twist-off with a hexagonal boss for a socket wrench) and remove the strainer screen. The bottom of the check valve ball is then accessible with a fingertip. Pressing on it a few times should free it up. In my case, it came free with a palpable "click". Reassemble and the engine should start right up as soon as the float bowel refills.

.

I've had the same issues/symptoms with facet pump(s), as noted in my current thread on fuel pumps. I suspect not all facet pumps are created equal, even of the marine quality. Either that or different fuel additives cause the ball valve to stick.

[joe_db]

Well one of my Facet pumps does not look very good right now


They do have their issues including a mode where they burn up slowly without blowing a fuse. They are used in a ton of airplanes and you can find them damaged like this in airplanes too! (lucky for the passengers these pumps are a backup for either a mechanical pump or gravity)

I would like to repeat - absent gauges you can replace everything including the engine and STILL not know why it quits. One friend had a freaking RAG in the fuel tank that would get grabbed by the pickup every now and then. Found this with a vacuum gauge

[EJORG]

Thanks for the Consistent Responses!

Adding to Ed's first hand experience, if the pump delivered 20 years of reliable operation maybe it's time to retire it with a thank you for a job well done. I'm not concluding the pump is the problem but there comes a time when it has served its useful life and I suggest you're there.

Just to clarify, the Motor has been reliable for 20 or more years but this pump was replaced maybe 5 years ago. I can't find in my notes why I replaced the old unit, but it was rusty and I was a bit concerned about its longevity. That said, I am sure that replacing it now would be the right next step. I am very grateful for the terrific responses I have received. I Feel I am on the right path.

I appreciate the comment about the vacuum gauges and also that about removing the fuel lines over the barbs on the fittings. That's not something I'd thought a lot about, but I will replace the fuel line at least from the filter to the fuel pump and also the line from the fuel pump to the carburetor when I swap out the Facet. I also am interested in the comment about the ball valve in the base of the pump. I have removed that lower filter basket in the past but never fiddled with the ball. It will be good to have that up my sleeve if I ever find myself in this situation in the future.


Thanks!

[tenders]

I feel as though I get limited information out of my vacuum gauge but the cheap little fuel pressure gauge is indispensable. I agree that the fuel pump is PROBABLY the issue here, but definitely pop in a fuel pressure gauge as you're doing this.

[joe_db]

I feel as though I get limited information out of my vacuum gauge but the cheap little fuel pressure gauge is indispensable. I agree that the fuel pump is PROBABLY the issue here, but definitely pop in a fuel pressure gauge as you're doing this.

If you have vacuum on the inlet side of the pump, the filter or pickup is clogged. If you have vacuum on the inlet side of the filter, the pickup is clogged. This is what I had and it drove me nuts because when you stop the clog drops back off.

[tenders]

Oh, you meant FUEL VACUUM. I can see the utility of that. I thought you meant MANIFOLD VACUUM, which is useful for fine-tuning. But I find so many other variables in a season's worth of use (mostly due to prop/hull fouling and short usage periods) that it is hard to get useful info out of it.