Decreasing Fuel Pressure
in General Tech Discussion
7 years ago
I'm chasing a problem with my Zodiac 601 HDS with Rotax 912 UL: after a few minutes in flight the fuel pressure is slowly decreasing. Normally, I see 5 to 6 psi, but it slowly keeps dropping to 20 psi. The engine never misses a beat, even at WOT. When coming in for landing and reducing throttle, the fuel pressure climbs up to 5 to 6 psi.
My setup: two leading edge wing tanks, each with the own electrical fuel pump, connected in series with the engine driven fuel pump.
Switching the electrical fuel pumps on or off does not change anything.
So far I have:
- replaced all fuel hoses in the engine compartment
- replaced one of the electrical fuel pumps
- temporarily re-installed an old Pierburg mechanical fuel pump
- replaced the fuel pressure sensor
- cleaned the fuel filters multiple times
- checked the fuel flow with the electrical pumps on - there is plenty of fuel flowing to the carburetors
I have read through multiple forums and have found several indications, that folks had a similar problem, but I never found a solution or an explanation.
I'm completely out of ideas. Any help from you is highly appreciated.
Thanks
My setup: two leading edge wing tanks, each with the own electrical fuel pump, connected in series with the engine driven fuel pump.
Switching the electrical fuel pumps on or off does not change anything.
So far I have:
- replaced all fuel hoses in the engine compartment
- replaced one of the electrical fuel pumps
- temporarily re-installed an old Pierburg mechanical fuel pump
- replaced the fuel pressure sensor
- cleaned the fuel filters multiple times
- checked the fuel flow with the electrical pumps on - there is plenty of fuel flowing to the carburetors
I have read through multiple forums and have found several indications, that folks had a similar problem, but I never found a solution or an explanation.
I'm completely out of ideas. Any help from you is highly appreciated.
Thanks
