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Steve, Sounds normal to my experience. I set the prop to fine and let it coarsen with revs. What ever works in that regard. I found an idle of 1800 rpm plus best even to 2000. Once you open up if missing you need to lean fuel off. The trim pot should give you an indication by turning to lean. Your lambda of 1 is interesting as the lambda is supposed to be over 12.5 preferably 13.5 even 14 at full power. That is what worked for me. I guess it depends what reading your lambda is tuned for as in giving a reading. To repeat my experience to stop missing was to lean out the mixture, a lot from what you are saying. Neil.
-----Original Message----- From: steve Izett
Sent: Wednesday, January 6, 2016 10:51 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Tuning
Hi Guys
Could I get some feedback on process and my thinking here.
I’m seeking to tune in our EC2 Renesis 4 port with Elec adjustable prop
Steps so far (can only run for 15mins before overheating)
OAT is presently 33-40C 91-104F
Prop set course
1. EC2 Injector and Coil diagnostics all good
2. With 2 squirts she starts well after approx 2-3 revs of the starter.
3. Run her up to ~23” and adjusted Injector Flow Rate - Mode #3 for approx Lamba of 1 on Wide Band
4. Set Idle of approx 1200RPM Adjusted Injection Dynamic Range - Mode #2 for same.
All OK to this point. Adjustments made in Mode #2 and #3 of EC2 reflect clearly on Wideband O2.
Switching between A and B computers makes no difference.
Now opening throttle up gets us to approx 5000 rpm (course Prop) but its missing as more power comes on and is quite severe. (Not missing now and then, but constant)
Selecting between A and B computers (Backup CAS) makes no difference)
THINKING
It has to be either fuel or spark right? (did do basic compression check some time back and saw fairly consistent pulses from all chambers)
Fuel
Fuel Pressure at rail is OK I think @ 34psi
Injectors were cleaned and flowed.
Good filtering in place
Fuel - premix
Spark
4 x D585 coils with New Leads I fabricated
Cleaned New Plugs (both T and L are 9’s)
How do I diagnose whats causing the missing?
Spark:
1. Check Timing - thought this has to right mechanically on Renesis - How do you do this on Renesis - reference - timing wheel? - What should we see at say 1200RPM?
2. Run her up in the dark to see any breakdown in ignition leads etc.
3. Put CRO on CAS signals? (EC2’s do appear to have mods done to CAS inputs soldered to bottom side of board)
3. Have had 2 newer plugs
Fuel:
1. Rerun making careful observation of AFR and fuel rail pressure.
Other thoughts
Rerun with reduce Prop pitch - Is missing RPM or Load related?
I will seek to record (video) engine parameters next run so I can review actual data in case I’m recollecting some parameters wrongly.
—————
Am I missing something?
Any recommendations?
Thanks
Steve Izett
Perth Western Australia
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