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Andair Fuel Pump Problem

Flyguytki

Flyguytki

Well Known Member
Ok Gents, I am getting ready for the first engine start this weekend so I started by flushing the tanks tonight. After the right tank was flushed with 10 gallons, I disconnected the fuel line at the firewall and directed it into a fuel can, went inside and hit the fuel pump and all i hear is a high pitched wine from the pump, (doesn't sound like a fuel pump running). After about 4 seconds the fuel pump will shut it self off, according to the VPX when the pump is making the sound it draws 1.4 amps and then shuts itself off too 0 amps. The wiring is correct as it is only a red and black wire from the pump. Can anyone think of what this might be? something I am forgetting maybe? I have attached a video so you can hear what sound the pump is making.

https://www.youtube.com/watch?v=giQ3_nV0DKQ


thanks

-david
 
I've heard these pumps can cavetate when there is air near the pump itself. I think someone sucked on the hose to pull the fuel through the pump (ick). Just don't swallow I imagine. Also, I noticed your fuel selector was on LEFT - is that intended? You may want to double check what the selector is on and which tank has the fuel in it.
 
Your right it was on left when I took the video, I had switched it over to see if there was a difference and there was not. Also I just went back out and sucked fuel through and there is no change. Still stumped.

-david
 
It doesn't sound like mine either - when mine is powered on there is a definite pumping noise, lower pitched sound. Perhaps Andair will have to answer what the issue is.
 
not right...

Mine draws a steady 6+ amps and makes a constant whirrrrrrr sound... try powering it directly bypassing the VP control. These pumps are self priming to 10 feet of head and will suck like crazy if it is working correctly.
 
I still have not found the culprit to the fuel pump however I did have to hurry and come up with a solution. This weekend I have my family flying in to help out with the Weight and balance, fuel tank calibration and first engine start and this fuel pump would prevent just about all of it. So a 2 minute phone call later and just about a thousand dollars and Aircraft spruce will deliver a new fuel pump to my house tomorrow.

Andair was not to helpful as this week is the paris air show so all but the receptionist are out, I am seriously hoping that when they return they will do a direct swap for a new pump which will soon be posted on the site for sale. So if your interested in a new Andair Fuel pump stay tuned and I might just have a deal for you.

Once again, the small things will hold you up, and cost you much more than they should.

-david
 
Same thing happened with my pump- I hooked up a hose and gave it a suck. As usual when I try syphoning I misjudged it and got a mouthful but it solved the problem. Pump flows over 50 gallons per hour.
 
Putting a hose on to suck fuel (prime) seems a bit like pushing your car rather than drive it. The whole point of that pump is that it's self priming....if it won't, then its malfunctioning.... isn't it?
 
It sounds like a locked up three phase DC brushless motor or bad electronic control. I install and repair up to 1 HP models of this type of motor. Efficient, powerful, usually low maintenance and very expensive. That is why I went with Airflow.
 
ColoRv said:
Putting a hose on to suck fuel (prime) seems a bit like pushing your car rather than drive it. The whole point of that pump is that it's self priming....if it won't, then its malfunctioning.... isn't it?
Click to expand...

I do not believe any of these pumps are self priming no matter what is said about it. They will not suck air.

If there is fuel in the line they will suck fuel up hill, Jan Eggenfellner sucked fuel to the top of his hangar when testing essentially the same pump sold by AFP and Vans.

But if there is air in the pump or in the line upstream, forget it.
 
David-aviator said:
I do not believe any of these pumps are self priming no matter what is said about it. They will not suck air.

If there is fuel in the line they will suck fuel up hill, Jan Eggenfellner sucked fuel to the top of his hangar when testing essentially the same pump sold by AFP and Vans.

But if there is air in the pump or in the line upstream, forget it.
Click to expand...

This is exactly right, one thing to add is on the andair pumps they use fuel for lubrication. What the issue was, was that the pump had been sitting for 2 years and like was said previously it will not suck air. After sucking fuel through the line and letting it sit overnight the pump is now operational. Thanks for all the ideas this site sure can save you a lot of money just as my h as it can make u spend it :)
 
Hi David,
I talked to Andy (from Andair) on the AERO-Expo this week and he said that having it sit for an extended period of time might be the culprit. He suggested spraying a bit of oil or WD-40 in the inlet and trying again. You basically did that so there's no need for option 2 of sending it back to them so they can take a look at it.

Andy also said they're easiest to reach by phone.
 
Mario Thanks you so much for talking to them, thats a huge help, Seems they know their product well, after you let fuel sit in the system over night it fired right up and worked great.

Thanks alot !!!

-david
 
I am having this same exact problem with mine. I also sucked fuel through and am letting it sit soaked in the fuel filled line and hopefully that will rejuvenate it. Otherwise I will have to call Andair and reschedule my DAR visit.
 
You should be fine, as long as fuel got sucked through the pump, give it an hour or so and it SHOULD be just fine. At least thats what happened with mine.

-david
 
Pump is still dead even after 3 days baking with fuel in the lines/pump. I spoke with Andy at Andair and he mentioned that they suspect the fuel they used to test the pump before shipping has possibly seized up. He said at the time they never suspected these would sit on the shelf unused for as long as we do when we are building. They now flush all the fuel and preserve them before shipping now.

He suggested in my case since mine was made in 2011 is to remove it and try putting some oil inside and cycling the pump to see if it will come unstuck. If not, they want it shipped back to repair.
 
Hmmm. thats no bueno. The only thing i could think of is what Andair said about putting a little oil in there, its completely off the wall and I know you are already doing it but its worth asking, Are you sure your supplying 12 volts to it? That could have a affect. maybe.

-david
 
Hum-----
This is an interesting thread. My Friend Dennis has a AFP in his RV8, and we did a first engine run last weekend. AFP pump primed immediately. So, I'm not certain of the priming issue with the Andair pump.
Tom
 
Tom, it's not a priming issue, but a known issue (at least at Andair). Back in 2011 and older, they tested all pumps and packaged them up. They did not flush out the fuel and have seen a number of these pumps seize after they sat for a long time. It doesn't affect the pump if put into use soon after purchase. They are now shipping all units with preservative oil to combat this situation. But mine was just old enough from my build to be part of the old process.
 
So here's the latest issue with the pump. It's not seized up, but now I need to figure out what's causing the problem.

I have the pump connected to the J12-12 pin on a VPX sport and have it set to 6Amps. When I power up the pump it still makes the weird pitch noise for a few seconds and then shuts off. I removed the pump today and connected it to my bench power supply (also 12V) and the pump worked! I reinstalled the pump and it went back to making the same noise. I connected the bench power to the pump while it was installed in the plane and it worked. So it has to do with the power in the plane. I used the multimeter and verified that when the assigned switch is triggered, the voltage on the line goes to 12V. I checked the ground from the pump and even used a different ground point ? no go. All the wiring is 18Awg, the +Vdc is about 10 feet long. The only thing I didn?t do yet is yank the pin out of the J12 plug and connect my bench power supply to it. When the pump is turned on, the VPX (via AFS EFIS Screen) draws up to about 2A briefly before the pump shuts itself off. Occasionally the VPX will show a fault and requires a reset when this occurs ? but not often.

I am wondering if my +vDC line is perhaps too small of gauge?
The crimp connector for the J12 pin is bad
J12-12 is bad and I should try a different pin to see what happens
Increase the amperage for the pump assuming it has a momentarily higher initial need. Spec sheet just shows 6A max (http://andair.co.uk/pdfs/PX375-TC.pdf)
 
I used 16 ga to mine. You may be reading 12V open circuit voltage when checked but when motor is in the circuit your voltage drops too low. Check voltage after pump is energized.
 
All the wiring is 18Awg, the +Vdc is about 10 feet long.
Click to expand...
I am wondering if my +vDC line is perhaps too small of gauge?
Click to expand...

It may be and why is it 10 feet long?
Just hook up a jump lead to your main bus and see if the pump runs, don't see why it wouldn't after it's been running on your bench.
you'll confirm that you may actually have a VPX problem not an Andair pump problem.
FWIW, my pump wiring is 16G and less than 5 feet long protected with a 5 amp SCB.
It sounds like you are closing in on the problem hope you get to the bottom of it.
 
The 10' is a rough estimate of wiring from the copilot side off of the VPX along the panel, the side fuselage under the pilot seat and then up the tunnel to the pump. It is likely to be under that length, but wanted to over estimate just in case.
 
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