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Geoff

I purchased my AFP electric fuel boost pump a little over 3 years ago. Before installing the top front skin on my RV-8, I decided to make sure the thing actually pumped fuel in addition to just turning on with the application of 12V. Turns out it didn't pump a darn thing. After talking with Don at AFP, I removed it from the airplane and tried to suck gas out of a can straight into the pump (bypassing the check valve and the return valve), but it still didn't work.

I sent it back, and they discovered that the pump had dried out after 3 years on the shelf. Once they re-moistened the innards, it worked just fine. I'm told they've subsequently solved this issue by selling new pumps with lubricant inside to prevent them from drying out during extended shelf time. However, if you bought your pump several years ago and haven't tried it, be sure to try to pump some gas with it before the final installation and loss of easy access. If you bought an earlier-model pump and it dried out, you may have to remove it and pour some gas through it to re-moisten.


Now for the questions...

1) Should I remove the fuel pressure line at the transducer and run the pump to get the air out of the line, similar to what people do with the oil pressure transducer line prior to the first engine start?

2) What is a typical GPH reading for fuel flow exiting the AFP pump when the exit line is just sticking into a gas can? I'm showing 50ish GPH with free flow into a can.

3) After reconnecing everything in the fuel system and pressurizing it with the mixture in idle-cutoff, I get 29 PSI with the AFP pump on. After turning it off, the pressure doesn't drop much at all -- like only down to 20 PSI after an hour of sitting there. Is that acceptable?

Thanks.

-Geoff
RV-8 (final ?? percent)
 
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I did nothing to my tansducer line and fuel pressure readings are fine.

I believe mine pumped out around 60 gph, but roughly measured. More than adequate at 50. I believe you want at least twice the max. fuel flow.
 
Not sure

Bob Collins said:
any idea when they started putting the lubricant in. I bought mine a little over a year ago.
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They didn't tell me that. However, if you test yours and it doesn't work, just pour some gas through it and try again -- it'll probably work fine then. At least that's what they did to my pump when they had it on the bench.

-Geoff
 
1) Should I remove the fuel pressure line at the transducer and run the pump to get the air out of the line, similar to what people do with the oil pressure transducer line prior to the first engine start?
I would leave the air in, to act as shock absorber for any rapid pressure fluctuations the engine driven pump might make.

2) What is a typical GPH reading for fuel flow exiting the AFP pump when the exit line is just sticking into a gas can? I'm showing 50ish GPH with free flow into a can.
That is more then enough.

3) After reconnecting everything in the fuel system and pressurizing it with the mixture in idle-cutoff, I get 29 PSI with the AFP pump on. After turning it off, the pressure doesn't drop much at all -- like only down to 20 PSI after an hour of sitting there. Is that acceptable?
Yes, no problems there, Just shows you mixture valve is not able top leak profusely and the servo then holds the pressure for a while.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."
 
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