Fuel pressure/flow problem
in 912 / 914 Technical Questions
8 years ago
I bought a flying Van’s RV-12 with Rotax 912ULS. Total time on engine is 70 hours. The engine has the new style fuel pump 893110 S/N 13.4493. The engine monitor is a Dynon D-180. I am getting alarms for both high fuel pressure and high fuel flow. Pressure has been as high as 12psi and fuel flows as high as 13gpm. These conditions are spikes. Normally the fuel pressure is steady ~ 7psi and fuel flow is 4-5gpm in cruise flight. The RV-12 has an electric fuel boost pump that is always on. I have pulled the electric fuel pump fuse on occasion and this seems to reduce total fuel pressure. The pressure increases when throttle is reduced in the landing pattern. Sometimes the pressure may also spike in cruise flight but not very often. High fuel flow only happens once in awhile and only happens during cruise flight.
I’m trying to troubleshoot this problem. Is the fuel pressure regulator built into the mechanical fuel pump? Is it adjustable? Does this sound like a mechanical fuel pump problem? Perhaps the fuel pressure sender is going bad? Is the fuel pump capable of producing 12psi. Lastly, can the carburetors work at 12psi fuel pressure?
I’m trying to troubleshoot this problem. Is the fuel pressure regulator built into the mechanical fuel pump? Is it adjustable? Does this sound like a mechanical fuel pump problem? Perhaps the fuel pressure sender is going bad? Is the fuel pump capable of producing 12psi. Lastly, can the carburetors work at 12psi fuel pressure?
