Is There a Fuel Lift Pump Which Can Beat My Fuel Tank Airlock ?

[Duke 48]

Installing the pump down stream will provide filtered fuel to the pump. Installing up stream forces air out of the RACOR.

[Noname]

Originally Posted by Shanaly

thnx all - 2 tiny queries
1 some say extra pump upstream of Racor, some downstream. what is the reasoning?
2 Doug Brown mentions bleed screws, are we talking on the extra pump/ on the filter / on the fuel lift pump / at the injectors?

The bleed screw is on the top of the small fuel filter. Loosen it a turn or so to let the air come out while priming with the electric (or manual) pump.

[casual]

Adding an electric pump.On my prievous boat all I,had was an electric pump,when changing fuel filters it was a simple job change them turn the key switch pump started bleed the systen thru the fuel retun line for 60 seconds or so and all was ok.Now I, have a manual lift pump.I,see some of you have installed an electric pump for the reason of bleeding after filter replacement.why not do away with the lift pump,put a plate over the mounting area and only uses the electric pump am I,missing something?It seems this would solve bleeding problems .Thanks for the input

[boatpoker]

Others suggestions are good but in the meantime and as someone else said your lift pump should easily handle the lift. ...
take your lift pump off, open up the top plate, remove the mesh screen take out the diagphram and mesh screen and inspect for dirt, grit etc. Take a close look at the neoprene grommet securing the bead on the fuel line and ensure that it has not swollen or is otherwise degraded.

This is an easy job and may solve your problem. Even if this works, I'd still add a bulb or 12VDC pump to make life easier in the future.

[hpeer]

FWIW Walbro makes some pretty nifty lift pumps.

About Walbro

My Yanmar lift pump works for 5+ feet, steel hull, integral tanks to bottom of keel.

But my Espar heater needs a lift. So I have one on that which works "on demand." It only gives a kick when the output pressure falls below a small prescribed value. Hence very low current draw. Cost about $140.

FRD Model Features:
· Flow to 153 lph (43 gph)
· Pressure to >12 psig (81 kPa)
· Maximum current requirements 1.5 Amps
· Up to 70% current consumption than FRA & FRC Models
· Reverse Polarity Protected
· 12 or 24 Volts Available
· Self priming
· Dry lift to 120” (305 cm)
· Output Pressures Available: 4, 6, 8 & 10 PSIG
· Compatible with all commercially available pump grade gasoline, gasohol, diesel or bio diesel
· Continuous duty life (diesel fuel): >10000 hours
· Dry run: To (4) hours
· Overall height: 5.35” (136 mm)
· Overall diameter: 2.76” (~70 mm
· Pump centerline to base of mounting bracket: 1.58” (40 mm)
· Mounting bracket width: 3.0” (76 mm)
· Weight: 1.56# (0.71 kg)
· Dichromate or E-coat external finish option
· Operating temperature: -40F ~ +155F (-40 ~ +68C)
· U.S Coast Guard Test #16623-1 and #16623-2 Certified
· European Standards EN 61000-6-2-2001 and EN 6-3-2100 approved

[captain465]

One other thing about an electric pump in the fuel supply circuit........if the racor filter becomes plugged with "gunk", the extra pressure/suction supplied by the electric pump, can get you out of trouble if need be.

[belizesailor]

Originally Posted by Dhillen

Another thing that we found works well in this situation is to install one of those squeeze ball in line pumps found on outboard engine fuel lines. We put one in line after the fuel pickup line comes out of the tank (make sure you don't put it on the fuel return line)! When we ran dry (every now and then, I'll admit) a couple of squeezes on the ball would push fuel right up to the lift pump and it was easy to bleed the injectors then. Before we did that we (meaning me) would be bent over the engine (usually hot) and flipping that little metal lever up and down about 500 times (rich, choice language followed with increasing volume) until fuel finally arrived. We had a Perkins 4-326 at the time.

Good luck.

DHillen

+1.

I use the same set-up on my boat (and on the previous boat). Very handy for maintenance, dead simple, requires no electricity, and you can find replacement bulbs almost anywhere in the world. With this set-up on my Volvo I don't even have to bleed the system manually -- prime everything well when changing filters, fire it up, then use the bulb to add some pressure if the engine starts to falter. Any air bubbles work their way out through the return line.

An added bonus, I was delivering a boat once with this set-up. It had sat unused for a long time so had lots of gunk in the tank. Of course, just as we were making a tricky marina entrance the engine began to stall due to a dirty fuel filter -- I used the bulb to keep the pressure up just long enough for us to get in.

[s/v Jedi]

Originally Posted by Shanaly

thnx all - 2 tiny queries
1 some say extra pump upstream of Racor, some downstream. what is the reasoning?
2 Doug Brown mentions bleed screws, are we talking on the extra pump/ on the filter / on the fuel lift pump / at the injectors?
3 i have 4 injectors, firing order 4-1-3-2, in principal do i crack all of these or just some as i turn the engine over?
THANKS again to all. (the fuel bulb works well, but yes diesel does slowly dissolve them. one day i'll put in an 'extra loop' to facilitate addition/removal of the bulb with out creating extra airlocks - also for the 12v extra fuel pump)

There must be a filter between the tank and the pump. Never fail to oblige to that rule

I wrote a piece on fuel systems for sail boats that includes what you want... just isolate it from the system or build it all for the ultimate setup
Here's the blog post: A new fuel system for Jedi (English) - s/v Jedi

Here's the Walbro pumps I used:

ciao!
Nick.

[delmarrey]

Originally Posted by Shanaly

thnx all - 2 tiny queries
1) some say extra pump upstream of Racor, some downstream. what is the reasoning?

If you put the pump first in line there is a chance it could suck up some junk and quit. But your tank should not be that dirty to start with! But after the filter would be OK if it does not need to be primed. IAW can it suck the air out of the filter vs pump it thru.

2) Doug Brown mentions bleed screws, are we talking on the extra pump/ on the filter / on the fuel lift pump / at the injectors?

Bleed screws are normally on the filters that come with the motors, whether it be the secondary or the only filter.

3) I have 4 injectors, firing order 4-1-3-2, in principal do I crack all of these or just some as I turn the engine over?

Normally you bleed the air with the motor running, or cranking the motor if it won't start. But that takes two people unless set up with a portable switch.

THANKS again to all. (the fuel bulb works well, but yes diesel does slowly dissolve them. one day I'll put in an 'extra loop' to facilitate addition/removal of the bulb with out creating extra airlocks - also for the 12v extra fuel pump)

You can put in a 3 way valve (for diesel) to bypass the pump when not needed.

[Cheechako]

Generally pumps push much better than they pull. (Even big pumps rated at a 200 foot push may only have a 10 ft lift or less.) I have always put them first after the tank. It would take a pretty big chunk of goop to plug the pump. Your fuel should be at least that clean! Those Walbro pups Jedi shows are the "Creme de la creme", although more expensive...

[Target9000]

Shanaly,

I'll second the above post about the mechanical lift pump being able to prime your system. (post #4 by Boden) It SHOULD work. The problem is that if the engine stops with the cam at exactly the right spot it will not. Try turning the engine over with a quick turn of the key but not trying to actually start it and then try again. This will change the position of the cam. Try it a couple of times.

To answer your questions.
1) (If you add a lift pump) Put the lift pump behind the filters. That means it should look like this... TANK -> Racor -> electric lift pump -> mechanical lift pump -> injector pump -> cylinders
The reason for this is that you want all of the fuel passing through the electric lift pump to be filtered and there for make it less likely to clog the electric lift pump. Also if you install an electric try to find one without the internal filter. Many come with a 100micron filter that will eventually clog.
2) Bleed screws are on the motor somewhere. Usually around the filter on the motor. Look in your particular motor manual.
3) Once again, the bleed procedure will depend on your motor. On ours you do not have to crack the injectors to bleed the system. Double check. It would seem a real PITA to have to crack injector nuts just to bleed a system. Usually if you bleed up to the injector pump you're good.

[RaySea Lady]

Originally Posted by Cheechako

I've done this before and it is an invaluable resource to prime the system after changing out fuel filters etc. Also will double as a lift pump if yours fails. I just installed it a couple feet from, and above the tank. Put a switch right next to it.
I have used a squeeze bulb before,however, I found it went rather mushy after a year or so...and the hoses also.... maybe the diesel degrades it?

Invaluable is a good adjective in this case.

On my cummins I could manually pump that little thump pump for half an hour for each engine. I installed a little 12v pump right at the tank with its own switch and had my mechanic make me up a manifold with an inlet from the pump and 5 outlets, each with a shutoff valves going to each racor primary and to each engine secondary filter as well as a line (hose) with a valve at the end in case I need to draw diesel fuel for something.

That was 4 years ago and I have used it every time I change filters and twice when I had switched my racors while the engine was running and I had air in the second racor. Took me 5 minutes and I was going again. I just have to remember to turn off the fuel supply to the engine while I run the pump and turn it back on after and all is good.

Invaluable is good ! I love it.

[delmarrey]

Took a picture of my setup today.....

I have a T at the tank. One side goes to the pump, the other to the filter.

There is a three way valve between the filter and the tank. One side goes to the outlet of the pump, and the other to the T at the tank, the third side to the filter.
With the valve in #1 position the fuel flows from the tank and into the filter.
With the valve in the #2 position the fuel flows from the tank, thru the pump and into the filter. IAW's the valve has two inlets and one outlets.

[Doug Brown]

Hi - you want the 12v pump to be installed down stream of the Racor - between the Racor and the engine lift pump. Having it located there allows "clean / filtered" fuel to be delivered to the pump - meaning your 12v pump will last a lot longer and won't get plugged up.

On my Volvo engine the housing mounted on the engine that holds the spin on fuel filter, there is a bleed screw. That is the one I loosen for either priming the fuel system with the lift pump or the 12v pump.

If you don't have a similar bleed screw, slightly loosen the nut holding the fuel injection line onto a fuel injector (the one most forward is easy to get to). This will allow the air to bleed out of the fuel filter and generally some/most of the injector pumps.

Failing that, you can also leave everything connected and just keep pumping - and eventually you will hear the fuel returning to the tank via the fuel injection return line.

Doug Brown