Don,
You can't rely on the mixture monitor reading if the engine isn't running right (missing, coughing, etc). Anytime the engine missfires for any reason, it pumps a load of unburned mixture (with a lot of oxygen) into the exhaust. Remember, the mix monitor is fed from an O2 sensor. It sees oxygen and assumes that the mixture is lean (off bottom of scale) so you may see this as the EM2 mixture display 'disapearing'. It has no way of knowing that the engine has misfired, it just responds to oxygen content in the exhaust.
The way to determine if mixture is the problem is:
Crank that manual mixture control in both directions to see if either direction helps. This is the only way to determine if mixture is the problem when you have a missfire, cough, backfire, etc. If the mixture control does not help in either direction, don't beat head against wall. Mixture is probably not the problem. Look elsewhere or yell for help.
Tracy
On Feb 17, 2008 10:44 PM, Bill Bradburry < bbradburry@bellsouth.net> wrote:
Don, if your mixture is not showing, you may be lean. Are you sure you are getting plenty of fuel to support the higher rpms? You may also be low on gas. When my tanks get low enough to unport the inlet, I get air in the line and the pump starts to squeal. If you have plenty of fuel, you may have an air leak letting bubbles in the line causing the same effect.
Bill B
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Don Wallker
Sent: Thursday, February 28, 2008 8:24 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] staging
The list has been a little quiet lately, so here goes. I'm the guy who couldn't get his Renesis going. Turns out a capacitor was missing for the EC-2. Then it would only start on a rare occation. Turns out it needed a 1000 ohm resistor across the CAS line as noise was changing the timing. Now, Stageing is difficult. Auto tune isn't really working and I have resolved that I will do it manually. It kind of works, but takes a long time and it's easier to just do it manually. My suspicion is that the manifold pressure is not holding steady enough, but now I am not so sure. I even added 2 ports near the throttle body, but it is still erratic. Even teed them together with the back ports. Now back to staging.
I get up to 19 inches, the staging * turns off and the engine start bucking. Tryed mode 6, setting for larger injectors (I am running stock renesis 295 primaries and 610 secondaries) Still bucks. Tried mode 6 turning down flow rate. At about 20 inches I was able to get it to even out, but it still bucks at 19, 19.5 and it bucks so bad that I can't get it to 21. I assume it is flooding as I was able to get it to run at 20 inches, but can't get it to change at any other setting. The EM-2 is erratic. The grafical mixture moniter, works and displays most of the time at lower manifold settings, but the higher the setting, the less it displays. At 19 inches, it only displays about 5% of the time. Kind of hard to set things if I have no feedback. Even stuck in a new O2 sensor to no avail. I can't run it long at these power levels, as I quickly get to 210 degrees. My suspicion is there is a root cause of all this EM-2 erratic displaey stuff. My very uneducated guess is that electical noise is causing all these problems. Your thoughts?? Solutions?
To add more problems, at high temps, I heard a squeel, then it stopped. Then it happened again. I didn't know what it was, so shut down. Couldn't get it restarted. Pumps sounded funny and no fuel pressure. Seems pumps over heated and cavitated as 5 minuets later, they started working. They are shielded and with a cool tube blowing on them. Apparently not enough. Your suggestions are very appreciated. Tracy??? Oh, yeah. If I disconnect the secondary injectors, it won't buck.
Frustrated RV-8 renesis builder
Now I'm e-mailing the Dynon list to find out why it won't display GPS data
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