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Fuel Hoses Pressure Testing

I'd like to have my fuel hoses pressure tested for a possible air leak. I replaced all hoses 2 years ago but have had fluctuating fuel flow on climb out for about the same amount of time since the hoses were replaced. In the interim I've had the fuel system overhauled twice and the fuel selector resealed all without resolution.

The fuel flow fluctuates during high power settings in the climb and is in the 1/2 GPH range. I had one event where after rotation the fluctuation was from the normal 25 GPH to as low as 18 GPH in the first 1000'. On another occasion it was a pretty high frequency of fluctuation but in the 1/2 GPH range. The 2 mentioned events both involved a long idle time waiting for clearance in hot summer weather although the 1/2 GPH is on every climb out. It smoothes out in cruise and when RPM's are reduced from 2500 to 2325 (my normal cruise setting).

Any input is appreciated and if there is a "best source" for pressure testing I'd be grateful for a suggestion.

Model: Bonanza E33A
Aircraft Serial Number: CE-297
Posted 4/24/2023 - 10 months ago
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Could this be a fuel flow instrumentation problem? Any changes in other engine performance parameters when you notice the fuel flow issues? Always ask yourself “what are we measuring?” and “how are we measuring it?”.

Posted 4/30/2023 - 9 months ago
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What is your fuel flow at takeoff?
Which engine model do you have installed?

Bob Ripley
ABS Technical Advisor

Posted 5/1/2023 - 9 months ago
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My engine is a IO-520BA and takeoff fuel flow is 26 GPH. I have a JPI EDM700 with fuel flow. Both the old Beech fuel flow gauge as well as the JPI show the 1/2 GPH fluctuation so it shouldn’t be an indication problem.

Posted 5/11/2023 - 9 months ago
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Dave;

Assuming that the pressure has been checked all the way back to the firewall and the fluctuation is not present there? If there is a fluctuation, it could be intermittent air entering the system from a fuel selector or aux pump shaft seal seep that is otherwise undetected (by smell or dye). And honestly, the hard lines can develop pin hole that could do this also.
If that is all good, contact the folks that built your hoses 2 years ago. It is in their best interest to make sure they are correct.

Mike
ABS Tech Advisor

Posted 5/11/2023 - 9 months ago
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Fuel Hoses Pressure Testing