1) Insure Dynon D120 software is current. Older versions allowed oil and fuel pressure to wander.
2) Insure Fuel Pressure Sensor is angled "up" to the hose to insure that no air bubble can get up to the diaphragm. For my 2009 SC, I rotated the Sensor counterclockwise about 15 degrees and made a 1" standoff from the host bracket to hold the hose and sensor in that 'up' position. This insures that no bubble will find it's way to the sensor and cause abnormal readings.
3) Fuel rate of flow can cause actual pressure to be inverse of flow rate. IOW - you go fast, flow goes up and pressure lowers a bit. Pump catches up and pressure comes back a bit. You turn final and drop the nose and cut the throttle, flow rate drops as you idle back and the fuel pressure can climb suddenly. Pressure bleeds away and fuel pressure indication changes.
So - keep fuel flow and residual pressure in mind as you try to sort the problem out.
Jeff Linger
Sep 15, 2016
Dave Bonnar
1) Insure Dynon D120 software is current. Older versions allowed oil and fuel pressure to wander.
2) Insure Fuel Pressure Sensor is angled "up" to the hose to insure that no air bubble can get up to the diaphragm. For my 2009 SC, I rotated the Sensor counterclockwise about 15 degrees and made a 1" standoff from the host bracket to hold the hose and sensor in that 'up' position. This insures that no bubble will find it's way to the sensor and cause abnormal readings.
3) Fuel rate of flow can cause actual pressure to be inverse of flow rate. IOW - you go fast, flow goes up and pressure lowers a bit. Pump catches up and pressure comes back a bit. You turn final and drop the nose and cut the throttle, flow rate drops as you idle back and the fuel pressure can climb suddenly. Pressure bleeds away and fuel pressure indication changes.
So - keep fuel flow and residual pressure in mind as you try to sort the problem out.
Cheers -
May 22, 2019