Dan Thomas
Touchdown! Greaser!
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- Jun 16, 2008
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- Dan Thomas
Looks to me like the leak is from the square-head plug, not the in/out fittings.
Fuel smell with boost pump io-360
- Thread starter FORANE
- Start date
Yes, it was the plug. It had no thread sealant on it.
- Joined
- Sep 11, 2019
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- Display Name
- Domenick
Did sealing the plug threads stop the fuel smell?
Don't know yet. We haven't run the motor since then. The other issue it developed recently was the fuel gauge started reading erroneously. I decided to tackle that issue at the same time as looking for the fuel smell.
The plane has one resistive type fuel probe in the header tank. This one:
Fuel Probe 12V 12In 5Bnd | Aircraft Spruce ®
Fuel Probe 12V 12In 5Bnd The probe is constructed of concentric tubing (a small tube inside a larger tube).
It would read correctly when powered on, then immediately when the motor started would start jumping around reading 8, 4, 6, 2, 5, etc all over the scale. It did this on both displays. I figured it was a ground problem. Turned out the old probe came out broken where the probe connects to the hockey puck base, presumably from vibration over time leading to metal fatigue.
We installed a brand new one but on the standalone display it read 5.8-6 gal when the tank was full with 9 gal.
This probe: https://www.aircraftspruce.com/catalog/ ... -03761.php
is a 0-5v probe. It should read 0v when empty and 5v when full. Today it is reading .438v empty and 2.8v full.
The Dynon HDX can compensate for these readings by calibration in the setup assigning voltage readings to gallon display on the EFIS. The standalone lacks this ability; it requires the probe output accurate voltage.
Here's the Dynon calibration:
Given that the standalone display controls fuel transfer from wing tanks to header tank automatically, and requires accurate numbers to do that, I need it to work. After getting run around by ACS, they agreed to accept a RMA. I've ordered a replacement probe in another brand and am AOG waiting on it. This is the new replacement probe:
Multi Set Point Fuel Probe (5 Bolt SAE) | RED Avionics
Capacitive Fuel Probe- Utilizes the same electronics as previously produced by Princeton Electronics.- Standard SAE 5-bolt pattern, Includes gasket- Can be configured to use 1, 2, or 5 set points- Available in 12, 18, 24 inch lengths (Can be shortened by installer) or can be custom ordered...