Hallo.
I have done a few hours of flight on my -4. It has a new Lycoming injected experimental IO-320. It has a Christen oil system.
During last months, a couple of times it runned rough after having idled preparing for landing (I have to idle way before landing in order to lose speed and height). One on ground, I pulled the mixture between half and 3/4 cut and the throttle all in to clean the spark plugs. The further flight went OK.
Yesterday during both landings engine went so rough that I had to abort the first landing fearing of an engine failure. Even increasing power gently didn't stop the faltering. Nearly the same on the homing landing, where I had to slip and lose height in order to land safely without going around.
I have to admit that during the last flights I use to power on the aux boost pump. I now suspect that the boost pump induce for flooded engine during low power settings. Actually, during the first landing I immediately shut off the pump and while for the next seconds the engine continued to miss shots, during the second approach, which became an actual landing, engine run OK (or at least I can't remember it run badly). I will for sure avoid powering on the boost pump in the future. While on ground, idle is wuperOK. Issues only when flying idle.
I was wondering is this can be a reasonable reason for the issue or if I have to investigate more. Actually, I can't trust on the engine and this makes me very upset.
Thanks.
Camillo
I have done a few hours of flight on my -4. It has a new Lycoming injected experimental IO-320. It has a Christen oil system.
During last months, a couple of times it runned rough after having idled preparing for landing (I have to idle way before landing in order to lose speed and height). One on ground, I pulled the mixture between half and 3/4 cut and the throttle all in to clean the spark plugs. The further flight went OK.
Yesterday during both landings engine went so rough that I had to abort the first landing fearing of an engine failure. Even increasing power gently didn't stop the faltering. Nearly the same on the homing landing, where I had to slip and lose height in order to land safely without going around.
I have to admit that during the last flights I use to power on the aux boost pump. I now suspect that the boost pump induce for flooded engine during low power settings. Actually, during the first landing I immediately shut off the pump and while for the next seconds the engine continued to miss shots, during the second approach, which became an actual landing, engine run OK (or at least I can't remember it run badly). I will for sure avoid powering on the boost pump in the future. While on ground, idle is wuperOK. Issues only when flying idle.
I was wondering is this can be a reasonable reason for the issue or if I have to investigate more. Actually, I can't trust on the engine and this makes me very upset.
Thanks.
Camillo
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