redundant system hand fuel pump

[sailingdolphin]

Has anyone ever added an outboard fuel bulb to the fuel line as a redundant system if the electric fuel pump fails.  Looking for input.

Thanks,

D& D #171

[Ray & Sandy Erps]

Hmmm, interesting idea.  I could see that one of those fuel bulbs might help when bleeding the fuel system as the little fuel pump on the RACOR filter can be a pain to operate.  As far as running the engine though, I think with a full tank of fuel, it runs down hill to the engine anyway.

[Stu Jackson]

Doug

You don't need one as long as your fuel tank is more than half full.

If it's less, even an outboard fuel pump thing wouldn't work unless you had someone pumping it all the time.

The best thing to do is to buy a backup fuel pump.  Do a search on Fuel Pump (type in +fuel+pump) on this board and you'll find the product number and lots of other information.  

Posted: Mon Nov 17, 2003 1:05 pm    Post subject:      

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Regarding the NAPA Part numbers provided by Ron Hill (above)...

The 610-51 should actually be 610-1051, and the cost as of 11/17/03 is $34.95...

According to Ron, it is basically the same as the NAPA 610-1011, but much cheaper...

[Ron Hill]

D & D : As the others have mentioned, you don't need a back up as the engine will run with out the lift pump.  
I've run for a number of weeks with out an operational electric fuel pump.  The fuel tank is higher than the engine.  In fact I've seen some boats where the factory miss wired the fuel pump to the spring loaded key switch position with the glow plugs!!  The owners didn't know the difference until I pointed it out to them.

The pump Stu mentioned has the same "innards", but is 1/2 the price because it doesn't have the filter.  Just make sure that the Racor is in-between the pump and the tank.  

[Ted Pounds]

I bought a fuel bulb for my system.  I didn't add it to the system; I just keep it in its original package with the supply of spares.  I felt that if I put it in the fuel line now it would just add another failure point.   My idea is, if the fuel pump fails and I need to pump fuel (to bleed or whatever), I'll pull the lines off the electric pump and put them on the bulb.

[Mike Vaccaro]

The "back-up" pump is unnecessary.  Like Ron and Stu pointed out, there is sufficient head pressure due to gravity feed without it.  After the tank level drops below about 1/2, on a starboard tack with any significant pitching motion, you may have problems with gravity feed.  The design of the system is simple and fairly clever--approximating the use of a "day tank" for feeding the engine.  A "day tank" is an auxiliary tank that is fed from the main tank and is mounted above the engine to allow for gravity feed. This is typical for boats that carry fuel in the keel or bilge areas.  

Although these small pumps are quite reliable and may run for decades, like Ron said, the only way you'll know it fails is by monitoring it.  The easiest way to do that is to turn the key (without starting the engine), and listen for a ticking sound at the pump.  If the fuel system is properly primed, the rhythm of this sound is fairly slow (about 1 tick per second).  If you keep your tank topped off to minimize condensation, chances are the only way you'll discover a failed pump is by checking in this manner, or when the engine quits under low fuel/heavy weather conditions.  To ease the ergonomics of monitoring the fuel system, it might be possible to either add a fuel pressure gauge or a light that would indicate that the pump is either running or failed (depending on how it's wired).  My personal preference would be to add an annunciator light that illuminated when the pump failed and is mounted at a convinent location that will be noticed.  But due to the "redundant" design of the system and the reliability of the electronic fuel pump, this is probably over-kill if prudent seamanship is exercised.  

Pitch for basic seamanship:  Just like a clogged filter, if you run into problems with the engine, the first job is to make sail and keep the boat going or get the boat anchored, then seeing to repairs.  This means that the boat is properly rigged to sail at all times and/or there is proper easily deployed ground tackle ready on short notice.  Over the years, we've largely lost the concept of the "auxiliary" part of the engine in the sailboat!  The utility of the boat increases dramatically with a reliable engine, but it's a mistake to ever depend upon it.

Cheers,

Mike

[Michael]

Mike:

As much as I like your pitch for basic seamanship, sailing under the bridges in False Creek in Vancouver, where we keep Hali, is a no-no so a problem we have in starting Hali's engine has become critical.

While I suspect a fuel pump failure - and have bought one of the "Posi-Flo" fuel pumps from Napa mentioned on this board - it is something of a who-dunit, at least for someone who has never dunit before.

We brought Hali across Georgia Strait from Sidney on Vancouver Island in a reasonable NWester, so the fuel tank got a good shaking up.

Then we ran the fuel down until there was only about 6 gallons left, as we wanted to pull the tank and clean it.

Notwithstanding the cleaning of the tank (yech - lots of crud after 10 years - four gallons of acetone over two days really didn't completely do the trick but there are no cleanout ports on the fuel tank that would allow a manual cleaning of the tank, which I think is probably the only real way of getting that gunk out) and letting the fuel line to the Racor (primary) filter run until the goop was out of it, too, we continued to have hard starting problems after as well as before the tank and line cleaning.  (There had been no hard starting before we crossed the strait and ran the fuel tank level down.  In fact, the engine had just been extensively serviced.)

After the tank cleaning, we filled the tank with about 60 liters (this is Canada - I guess about 15 US gallons) of diesel fuel and the engine started reasonably but soon - after we had burned off a couple of gallons I suppose, the hard starting problem (which occurred when we were below half a tank previously but also after the rough crossing) recurred.

We are going to try filling the fuel tank right up, so that the engine would run (as indicated by other postings) without a fuel pump at all.  If that seems to cure the problem, I suppose it will be some indication that the fuel pump is the culprit.

(I should add that there is electricity to the fuel pump, at least when the key is on and the master battery switch is on; and the fuel pump certainly runs sometimes, as we get that nice whirring sound sometimes.)

If anyone has any particular insights, they would undoubtedly be welcome.  (Expensive things like injectors and injector pump will be canvassed only when the inexpensive possibilities have been canvassed.)

Regards.

[Ron Hill]

Michael : Beside listening to the pump "feel it"!  You can tell that the pump is pulsating by feel.  I assume that you changed BOTH filters when you cleaned the tank?
What you might also want to try is some of the Starbright Fuel Tank Enzyme and see if that helps. Fill your tank and see if that helps.  A thought.   

[Stu Jackson]

Assume you've done the search on bleed and bleeding.  Sounds like that's your problem, check all hose fittings and clamps on your fuel lines.

http://c34.org/bbs/index.php?topic=3682.0

[Footloose]

Michael,

If your fuel system checks out OK, look at your electrical system.  I don't know if any upgrades were made between '88 and '97 but the early ones were weak.  Upgrading the wire terminals on the battery cables and installing a solenoid for the glowplugs will make a big difference.  I think your boat came with the wiring harness upgrade so you shouldn't have to do that.  Any resistance (one or two ohms) in the cables at the high amperage that is drawn by the glowplugs and the starter makes for a large power loss and therefore slow cranking and improper heating of the glowplugs.  Don't forget the terminals that go to the selector switch and on the engine.  Your boat engine should be as reliable as your car.

BTW:  I agree with Ron; it only took me about an hour to get the fuel tank out.  The longest part was draining the ten gallons of fuel that I had left.

[Michael]

Ron, Stu, Dave - Thanks for your follow up.  After posting above, I started another thread (http://c34.org/bbs/index.php?topic=3725.0) with more detail about this problem and only got back to this thread now.  I will follow up the advice here as well as on the other thread. Regards.