Low Fuel Pres w/Mech Pump
This scenario is occurring with my TL30 Sirius with a 912ULS
When at altitude with 5200 rpm, fuel pres drops to 2.0-2.1 psi. Problem alleviated by turning on the Aux Fuel Pump...brings the pres into the 4.2-4.8 range. What's odd is that during taxi, run-up and take-off, without using the Aux Pump, the fuel pres does not fall into the 2's. It only happens once I am at altitude.
Now...after landing and clear of the runway, I turn off the Aux Pump and the fuel pres remains in the high 4's. Plus there a faint smell of fuel.
Question 1: if I am losing pressure with just the mechanical pump due to a fuel leak, where would be the most obvious place to check the fuel circuit. All the hoses were just replaced as part of the 5-year advisory from Rotax.
Question 2: Prior forum posts advised not running the Aux Pump continuously. Is this what is generally accepted, even when experiencing low pres?
Mark Bearss, Brainerd, MN