First time starting it up yesterday.
We are building an RV14A with a Lycoming 390 Thunderbolt with duel Pmags and standard injection that comes on the motor.
We read the Lycoming manual and followed the steps.
In general it worked very well. But in order for it to run smooth the mixture needed to be moved a lot to accommodate the engine speed. It order to rev it up it needed more mixture. And the same with idle. But in the end it did run very smooth once it was adjusted for the range of speed. We live at 7000 elevation but it's a plane so it should not matter.
We have not done a fuel flow test yet but it measured fuel flow on the AFS screens and the pressure looked reasonably. And when the electric pump was on it seemed to pump too much pressure and you can hear it working well.
The question is it seems that it wants to run very lean and an adjustment is needed in the mixture/flow/pressure to allow for RMP/speed. On other injected planes I have flown the mixture "knob" is out about 1" + - and it just runs (at least at first rolling on the ground and starting run up). In our plane the mixture is about 1/2" from full off. And it constantly needs to be adjusted just to run well.
Does anyone have ideas to try?
Thanks, Larry
We are building an RV14A with a Lycoming 390 Thunderbolt with duel Pmags and standard injection that comes on the motor.
We read the Lycoming manual and followed the steps.
In general it worked very well. But in order for it to run smooth the mixture needed to be moved a lot to accommodate the engine speed. It order to rev it up it needed more mixture. And the same with idle. But in the end it did run very smooth once it was adjusted for the range of speed. We live at 7000 elevation but it's a plane so it should not matter.
We have not done a fuel flow test yet but it measured fuel flow on the AFS screens and the pressure looked reasonably. And when the electric pump was on it seemed to pump too much pressure and you can hear it working well.
The question is it seems that it wants to run very lean and an adjustment is needed in the mixture/flow/pressure to allow for RMP/speed. On other injected planes I have flown the mixture "knob" is out about 1" + - and it just runs (at least at first rolling on the ground and starting run up). In our plane the mixture is about 1/2" from full off. And it constantly needs to be adjusted just to run well.
Does anyone have ideas to try?
Thanks, Larry