Installing electric fuel pump

[okapi3]

I searched and surprisingly didn't find any threads on this. So here goes... on my new-to-me PSC31 I found in a locker a brand new electric fuel pump in its box. Right next to the fuel line, before the Racor filter, is a block with 2 mounting bolts that match the pump. Also right there are two electric wires with stripped ends covered with electrical tape, presumably for the electric fuel pump the PO had planned on installing. I would like to install this pump. My questions are: 1. Should I install a switch right there at the pump and if so what kind? 2. Should I run the pump whenever the engine runs or only to prime it or test for leaks? 3. If I want it to run whenever the engine runs how should it be wired (I haven't traced the wires yet to see how the PO set it up). Hope my ignorance isn't too annoying and thanks for the advise in advance.

[theartfuldodger]

You should check first to see what type of pump it is a pusher or sucker type, and its fuel pressure value, as is important to know amount of fuel pressure your engine is to handle. With that knowledge and if they are compatiable then use the wiring diagram which might be with the pump. If there isn't any check online and search for the make and model and its specs.

[danielgoldberg]

If you want it to run whenever the engine is on, wire it to the ignition switch so that whenever the ignition is in the "on" position the pump is running. If you want it to run just to prime and/or bleed, just run it to a free switch anywhere. Whether you want such a stand-alone switch at the helm, by the tank, near the engine, all depend on your personal preference and what you think you'll be using it for. For instance, if you want it just to bleed the fuel system you might want the switch by the engine. As another example, our generator has an electric fuel pump wired to the glow plug switch so that we're priming the system pre-start, but using only the manual lift pump while its running (don't ask).

As to whether you want to set up the pump to run whenever the engine is running, opinions vary, and it also may depend on your engine type. Check with the manufacturer to see what they have to say. If the engine runs fine with just the lift pump, there may be no need to add an electric pump while the engine is running (coming under the heading: If It Ain't Broke, Don't Fix It).

[camaraderie]

Note...the fuel pump must be installed between the Racor and the engine fuel filter...not between the tank and the Racor. Failure to follow this advice will result in frequent and often "inconvenient" engine shutdowns.
Don't ask how I know this!!
always cary a spare!! Don't ask how I know this!!

[okapi3]

Thanks for the advice. I like the "if it ain't broke don't fix it" advice in particular. Yeah, the engine runs fine with just the lift pump, but I learned (through a carefully designed experiment ) that if I run the tank bone dry the little lever just can't seem to pump the fuel all the way up from the tank through the engine! After some creative work with hand pumps, hoses and funnels to get some pressure head I managed to get it primed, but decided a little switch on an electric pump would be a lot easier. I'll be at the boat tomorrow and will see what I can rig up (but fixing the head will take priority). Thanks!

[danielgoldberg]

Originally Posted by camaraderie

Note...the fuel pump must be installed between the Racor and the engine fuel filter...not between the tank and the Racor. Failure to follow this advice will result in frequent and often "inconvenient" engine shutdowns.
Don't ask how I know this!!
always cary a spare!! Don't ask how I know this!!

???

I've seen installations both ways, but I actually think it's better if the pump is right at the tank. That way, if you have a leak you can find it without a vacuum gauge (cause diesel will be spewing out of your leak source). You do need to make sure your Racor filter can handle the pressure, but I think most can. For our genset we have the pump right after the tank in our setup, and have experienced no shutdowns.

I'm not disagreeing with you (yet ), but just curious why you think the "suction" install is better than the "pressure" install.

[camaraderie]

If you read the warranty that accompanies most small electric fuel pumps (NAPA for instance) it excludes coverage for pumps mounted without a filter in front of them. This is because eventually grit and debris from the tanks that is unfiltered disables the pump. The symptoms of a broken lift pump are exactly the same as those of a clogged fuel filter...the engine is starved for fuel and it quits, often when the seas have stirred up the bottom of the tank stuff. This may be less of an issue on new boats with clean tanks and using well filtered USA fuel supplies...but it is nevertheless an issue. I changed 6 fuel pumps (several different brands too!) in my first year of cruising till one day I read the warranty and the light came on. Moved the pump and NO further pump replacements in the next 2 years.

[danielgoldberg]

Gotcha. The pump we used had an internal filter, and we just replaced that periodically. In that boat we had the pump filter clog only once, but boy was that a pain until we figured out the problem. We kept sucking dry the fuel in the racor filter and couldn't figure out why, so we limped home through the night refilling the racor with fuel from a jerry can, and used a champagne bottle to pour the fuel directly into the racor. That was a McGyer moment and a story in and of itself.

Also, some people you run the pump without the internal filter at all. You just have to have at least one extra pump handy for when the pump fails due to no filter. At a cost of about $30, changing the pump is not all that more expensive than replacing filters.

I do see your point though, and I had forgotten about that. I still would install the pump right at the tank, and just make sure the element in the tank is clean and have spares for that. Nothing more frustrating than being unable to find an air leak in your fuel system.

[chucklesR]

My Westerbeke 27b has a electric fuel pump installed. I won't answer all the OP questions but will tell how mine is wired.

It is mounted on the engine, between the primary filter (80 micron) and the engine mounted secondary(20 micon) which is installed after the pump. There is an additional third filter (10 micron) installed directly before fuel goes to the injector rack. It is the highest part of the engine and fuel system.

MY pump turns on as soon as the ignition swith goes to the start position (you can hear it kick on and run). I have a rubber booted push button to press that fires up the pre-heat (8 seconds or so). All in all this gives the pump time to get up to speed pushing 25 gallons per hour thru the system. Fuel not used to run the engine (1.2 gallons at 3600 RPM) is returned to the same tank it came from, or the other tank if I forget to put the valves in the right place.
If, for example my port tank was empty I could polish my starboard tank by switching the pump on (not starting the engine) and having the valves set to dump the fuel into the port tank. 18 gallon tank, 40 minutes later I have clean, prefiltered fuel in my port tank. For that reason I genrally try to fill one tank, polish it, and run from the 'clean tank' as much as possible, in theory I have at least double filtered my fuel - in actuality the fuel passes thru the filters many many times before it is burned.
My entire system is self bleeding and requires nothing after a fuel filter change than simply turning it on and waiting about a minute to clear air out. I've never had an air lock. I have had a pump go bad (electrical connection) and I carry two spares onboard. One spare is mounted to a board with filters and valves installed so as to make a portable polisher that I can also use to entirely replace my filtering and pumping system in less than 5 minutes by simply connecting the hoses inline with the current system. If necessary I can run directly from a jerry can and dump excess right back to another can.

One time of having no engine in a squall is one time to many for me, never again.

[Rockter]

Oh dear, I am going to be contrary again.
The pump on my ship is installed before the Racor. It is the Stewart Warner 235A-D, and costs about $80. It delivers 5 psi.
Leaks are apparent at the Racor (or elsewhere) as the fuel dribbles out rather than air creeping in. Older Racors tend to leak a wee bit, and they are pricey. If you firt the pump after the Racor, you may miss the air being drawn in.
I failed a pump after about 15 years. The second one went in there last year.
There is a fire risk with them, as the fuel system is pressurised and it will feed quite a fire if a fire gets started, but what do you do?... do you risk drawing air on an old motor?
A pressurised system really does help starting and I have never had the motor stall once it has been fitted. Contrast that with the heart-stoppers of the distant past, when the motor would slow on entry to harbour, drawing air.
I have been there once too often.
The motor will still run if the pump is switched off, so there is a by-pass on it somewhere.
An idea would be to fit a wee LED and fibre-optic cable to warn you at the instrument panel when the pump motor is running. When operating, the pump is intermittent... rat-a-tat.... rat-a-tat... and you could feed the LED output to the dash. if a line ruptures, the LED will warn by staying lit continuously.... rat-a-tat-a-tat-tat-a-tat-a-tat.

Rockter.