Electric Fuel Pumps for Priming

[beltguy]

I was talking to Darryl Elkins about his new Eagle and we were discussing the benefits of having an electric fuel pump to prime and engine.

While there are all sorts of ways of priming the engine (air pressure in tank, pressurized weed sprayer connected to the primary fuel filter, etc), most people consider an electric fuel pump to be the best option.

There are two ways that electric fuel pumps are "plumbed" into the system. One way is to install the pump in a parallel circuit and control the flow with valves. The second way is to install a "flow through" pump in the supply line from the tank to the primary fuel filter.

The electric pump does not need to be powered except when priming the engine.

I use the parallel system on my bus. That way I can remove the pump and use it for other applications if needed. Whenever the subject comes up, Clifford always advocates the Airtex flow through pumps. I made a mental note (several times ) to research the Airtex pump options. Recently, on another board, a person advocated the Airtex E8016S: http://www.amazon.com/Airtex-E8016S-Ele ... B000C1LW0E

That unit is sized for 5/16 hose. Maybe that is enough flow capacity, but I would prefer something larger like the E8090: http://www.amazon.com/Airtex-E8090-Univ ... B000DN7VLK that has 1/4 inch pipe thread and 3/8 hose fittings.

Jim

[darryl97420]

I ended up running a second fuel line from the street side tank through the battery box to the pump. As long as the pump was plugged in the engine ran great. When the pump was unplugged the engine would run fine for about 5 minutes then become starved for fuel. Recovery is as quick as connecting power to the pump.

This made for a head scratcher and an interesting ride home.

[rusty]

I don't know anything about 2 strokes but it sounds like a weak fuel pump. Maybe a hole in the fuel line and losing prime, but with the second pump you should see a leak. I say weak pump because i don't think the motor would run for 5 minutes with a bad pump.

Wayne

[luvrbus]

Jim you are right I only use the E8090 mounted before the primary they don't restrict the return flow when I checked it with the pump off it was still about .9 gpm spill under no load which is where it should be.
Darryl's problem is that is not a flo/thru pump he needs to replace it with a E8090 flo/thru or valve around it like you have done.
The mechanical pump cannot pull fuel through his setup I run into that all the time with those little solenoid pumps people have installed.Those are transfer pumps gravity feed and just transfers the fuel if he changes it he will be good to go, the mechanical pumps either work or they don't no in between.
His main pump is working no way will his electric pump supply 70 psi and the flow rate to keep his 8V71 running

[darryl97420]

The pump I have is running parallel with the factory system and joins in at the primary fuel filter. When the electric pump is removed and the port capped. There is enough fuel flow to run the engine for a few minutes before it dies. My friend Eric who works on Detroit boat motors will see if he has a rebuild kit in his shop or a complete pump. We suspect that the tube coming from the main tank is collapsed or kinked because some fuel is getting through.

On my bus has 2 - 50 gallon aux tanks in the bays that are plumed to the main tanks. They need to be drained and removed, the lines capped and fuel line to the engine replaced. I had considered leaving them in there but value the bay space over an extra 100 gallons of fuel.

[darryl97420]

The 8090 fuel pump is scheduled to be here Monday and with that am looking at the engine bay trying to determine where to install the pump. Those who have installed an electric pump, where did you install it and do you have pictures to share?

[beltguy]

Darryl, I have not installed an inline electric pump - mine is a parallel system. That said, the general consensus is that electric pumps are better "pushers" than "suckers". May not be all that big of a deal, since we don't have to lift the fuel very far.

Jim

[darryl97420]

The E8090 showed today and as I am taking it out of the box I see a big notice not to use on aircraft, marine or fuel injected engines. Doing so will void any warranty.

Now I am going to install this bad boy anyway due to the success I've read here and I will run it inline.

Here goes something...

[darryl97420]

UPDATE

There is a guy down the street that has some old Flxible New Look and RTS buses in his yard and I've never been able to catch him at home till today. I told him about my bus and the prime issue and he agreed to come take a look. He looked around and asked if there was fuel in the tanks to which I said yes. Then he asked if there was fuel in the filters. I opened them and they were full. So he said start the bus what are you waiting for? I told him I hadn't installed the electric fuel pump to prime it. He looked at me and mumbled something that ended with "start the bus" so I gave it a crank or two and it started. Ran like a dream!

He played with the throttle looked at the exhaust and said that I've got a good strong motor that is firing on all 8 but it could use a tune up. I asked about how much that would cost to which he said this place was 120/hr, that place was 150/hr and DD in Eugene was 200/hr but he would tune it for 30/hr and some beer and it should only take an hour or two depending on who drank more beer, me or him.

Come to find out he is a retired DD rebuilder and has new and used parts at his shop along with his tools. He plans on showing me some stuff about the engine including maintenance then after that WE will give the old bird a tune up. I'm super excited about hearing her run!

Anyone need an electric fuel pump? Its never been installed...

[beltguy]

Darryl, how fortunate that you have that resource!!

I would not toss out the idea of installing the pump. If you ever loose prime, you will be very glad that you have that pump.

Some Eagles had check valves in the fuel line to keep the engine from loosing prime. That check valve can go bad and the fuel can siphon back to the tank.

Even though I have a pretty fool-proof fuel system with the Fuel Pro 382, I still carry a fuel pump that is plumbed into the fuel system (mine is a parallel system).

Jim