BlackRV7

BlackRV7

Well Known Member
I was planning first engine start tomorrow and in preparation put three gallons in the left tank. With the fuel select on left I turned on the facet electric pump to check for any fuel leaks. The electric pump will not prime as referenced by the continued clicking. What gives, any thoughts.
 
Priming

Dana,

I had a problem priming the first time, but it has always worked well since then. That will probably be the case there also. I am assuming you have double checked that all fittings are tight. Any air leak would prevent priming. You also might loosen a fitting downstream of the pump if there is any possibility of blockage. A full carb (don't know if you are carb or FI) with the float valve closed presents some resistance.

Bob Kelly
 
BlackRV7 said:
...The electric pump will not prime as referenced by the continued clicking. What gives, any thoughts.
Click to expand...
Mine has clicked for the last 8 years. Why does that mean it isn't priming?
 
Dana,
Although it isn't needed for a first engine run,
I did my fuel flow tests before ever starting
my engine. I found that there is only a subtle
change in the fuel pump's sound as the fuel
pressure comes up. Also, I filtered about a
gallon from each tank before returning it to
the fuel tank on another A/C.
My RV has a low pressure, (carb) fuel pump.
You should be getting some fuel pressure indication.

It sounds like 'Black Magic' is getting close,
Tom
 
Prior to my first start I couldn't get any fuel flow with my high pressure pump for my fuel injected engine. I finally gave the tank some head pressure through the tank vent and that got the fuel flowing. I was concerned that maybe the pump couldn't pull the fuel for whatever reason, so I did some tests. I let the tank run dry and put more fuel in it and it pulled the fuel without any problems. I also let it sit for a couple of weeks and still no problem. I concluded that after so long of sitting there during construction without any fuel, the pump itself had lost it's prime. It did come with some fluid in it, but when I was fitting the lines I took the caps off and the fluid drained out and sat that way for years.

Jerry
 
I agree with Larry....that pump just keeps clicking away, even when flowing a lot of fuel! Scared the heck out of me the first time I turned it on when it was empty - sounded like a little gnome was under the panel with a ball peen hammer, banging away on something. But even when it is full of fuel, it still makes the noise.

Of course, if you've confirmed that no fuel is flowing, disregard all....

Paul
 
OK here's the deal. I show no fuel pressure on my Dynon. I have no fuel at the carb. I lifted the tail, with the pump on, with no change in clicking or fuel introduction. 21 gallons per with 19 usable, my accountant thinking says numero uno gallons present for startup. What does the undoing of a fitting post pump do since the carb isn't pressurized other than a restricted jet? Inquiring minds want to know. Anyway, I want to start this bad boy up and fuel, or lack thereof, seems to be an.........issue to be politically correct. And BTW I pulled the throttle to idle, mixture to rich and ran the starter with the mags off, electric pump on, to see if I could "draw" fuel....no joy. I know, add more fuel except I can seem to find any 100LL around the house :cool:
 
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Dana, unhook the fuel line from the carb and see if you get fuel flow with just the electric pump.

If not, check to make sure you have the pump pushing fuel in the right direction and that the fuel selector valve is properly connected and set to the correct tank.

If none of that works, you could always suck on the disconnected fuel line with the pump off, just to verify that fuel will flow. Don't swallow any!

If fuel does flow, something is probably wrong with your fuel pump or its installation.
 
One other idea if you get into radical disconnection - disconnect the line at the pump inlet and shoot a little air back toward the tanks - see if you have a blockage upstream of the pump....(grasping at straws here...)

Paul
 
Easy enough

I used two of those pumps on my zenair zodiac...one in each wing root with no mechanical pump for 400 hours...Dang reliable, bulletproof pumps.

There are teo things that come to mind.

1) You got the pump in backwards...Very easy to do!

2) You have to get the inside of the pump wet before it will pump anything. What you have is a dry pump trying to suck air thru some restrictions a long way from the tank.

Hard to do.

So, drop the hose connections off the pump and attatch 4 feet of plastic hose on each end. Stuff a funnel down the inlet tube and force feed it some fuel...Run the pump....the pump will flow fuel and it will now be wet.

Connect the inlet piping, put enough gas in the tank (it doesn't have to be 100LL) and make sure fuel flows the temp tube.

Now connect the outlet piping up and it will pump normally.

I actually dropped the fitting off at my fuel injector and flushed the system for 20 minutes or so on each side before I pulled my filters to check for crud.

Good Luck

Frank
 
Back prime

OK, as of this morning the facet pump is installed in it's correct orientation. The valve is correct as I blew through the right and left fuselage connections points just a couple days ago to verify the valve orientation.

Question, can I back prime this pump from the firewall side back? This would be much easier than removing the wing. Gotta do what ya gotta do though.
 
Dana you don't have to take the wing off. I had the same problem when I first attached my wings to run the engine. Detach the fuel line at the wing, pour some fuel into the line going to the pump, turn the pump on for a second and the fuel should disappear from the line, turn the pump off, fill the line again. attached the line and turn on the pump, you'll have fuel pressure.........
Shine'r (Sunny, Warm, Clear Sky, Pittsburgh,Pa.)
 
Back prime

Dana,

Back priming sounds like a good idea. So does sucking on the pump outlet line. Anything to get the pump wet and remove any restriction. Also you might try pressurizing the fuel tank (VERY low pressure required) until some fuel exits through the downstream line. You will have to plug the vent line. You might also consider turning over the engine with the plugs removed as the engine pump seems to have more suction.

Two ideas at this point also: flush the system with car gas (saves money over 100LL.) I ran a couple of gallons through and did get some trash. Not a lot, but some. Also, blow through your vent lines to make sure they are open. I had a mud dauber build in the vent line into my left wing before I installed it. Could have been a big problem!

Bob Kelly
 
Okay...OT

Was talking to a friend of mine who was building a bearhawk...Had a beautiful IO550 Continental almost fitted up except the fuel line was disconnected and the bulkhead fitting was just poking through the firwall.

As we talked a bee flew into his shop and without any hesitation (or flying a standard pattern) made a "straight in" for the AN6 fitting and dissappeared inside!

It was so fast my buddy refused to believe me that there was now a bee inside his fuel system.

I wouldn't have believed it either but I know he flushed his fuel system real good!

OK back to work
 
Watch those fuel vent lines! I got a "Yellow Jacket" out of the fuel sump during a pre-flight and the only way in was thru the vent line. I now cover my fuel vents daily!
 
Thanks gang

I unhooked the fuel line at the wing root and attached a short hose to the fuselage fitting. I went to the nearest farm supply and bought a cattle syringe. Filled the syringe up from the pep **** and filled up the fuselage fuel line. Instant priming.............................only to find out I just may have a carb issue.......fuel likes to pour out the bottom of the FAB :eek: Oh well, I'll let the flood go away then try starting it using only the mechanical and throttle. I'll be judicious in throttle control this time ;)
 
I just may have a carb issue.......fuel likes to pour out the bottom of the FAB
Click to expand...

Dana, couldn't tell from your post if you were cranking the engine as you were priming, but if so be very sure you don't have a high pressure engine fuel pump as is used for fuel injection. It looks identical to the low-pressure unit you want for your carb, but the 30lbs of pressure it produces will instantly drown your engine and leave you with fuel running out the carb.

No need to ask how I know this...... :)

If the engine pump wasn't running when the deluge began then it sounds like the float needle valve is stuck. Try gently tapping the carb body with a small hammer in the area of the valve to see if it will seat.
 
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Don't do it!

Fix the overflow problem before you proceed! It is probably a stuck float valve, but it isn't cool to have fuel running around when you are starting an engine for the first time. The couple of hours it will take to troubleshoot this is nothing like what it takes to rebuild after a fire. Check everything out--tapping on the carb may do it.

Bob
 
Hi all, I was having the same problem with my Facet pump, the model I am using is the 40108 with the 3/8 male fittings either side of the pump body.

I would have spent at least 4 to 5 hours trying to get my pump to acutally pump fuel - OK so here's what I have learnt.
Firstly I was using an old battery that had suphated but I reasoned that the pump only drew and small amount of current (and it was reading about 13.5 Volts across the terminals) and I also had a 2 amp battery charger across the terminals as well I thought I had sufficent Oomfh to power the Facet-I checked the current it was drawing and it was reading 0.57 Amps but I could hear the pump ticking over so I thought it was working OK but thought it still wouldn't prime.

Finally in desperation, I put another battery in place and immediately I noticed a much deeper tone coming out of the pump and, I also backed off the fitting on the outlet side of the pump to bleed any air out and it was away and pumping strongly, I checked the current draw now that it was working and it was reading around 1.2 Amps which is what the specs say it should draw.

So if there is a lesson here is don't trust those old sulphated batteries we may have kicking around in our workshop-they probably have too much internal resistance to power even low current draw applications.
 
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