Mailing List flyrotary@lancaironline.net Message #6989
From: John Slade <sladerj@bellsouth.net>
Subject: O2 / EM2 problems.
Date: Sat, 3 Apr 2004 16:16:21 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Tracy said: 
Next time you get it started,  make sure you have fresh plugs & O2 sensor installed and run engine to ~ 22" Hg MAP.  Adjust mixture control to get a smooth run if possible.  Use mode 3 to get a mid range mixture indication at 12:00 on manual mixture control. 
 
Mode 3 has to be programmed with the engine running, but the mixture is so rich that the engine wont start.
I had something of a chicken and egg problem, Tracy. Even if I could get her running the exhaust was so full of soot that the sensor was getting coated  in a few seconds. I figured a way out of the loop this afternoon.
 
EC2 doesnt know the difference between fast cranking and running. I took out the plugs, selected mode 3 with the knob to the left, cranked for a few seconds, then hit the program button twice while cranking. I put the plugs back and she fired right up. No more black smoke. Now I'm in the ball park I can install a new sensor and do some fine tuning.  This might help anyone else with four 550 injectors. Just knock the overall mixture down a couple of notches while cranking, before even TRYING to start the engine and ruining plugs and sensors.
 
One other problem I found was a bit silly, but you can add it to you're list of dumb things people can do....
The mixture control knob had come off a few weeks ago, and a helpful friend had put it back on for me - 90 degrees out. There are 2 set screws 90 degrees apart. He'd tightened it up with the wrong set screw on the flat so the mixture was 90 degrees out. No big deal until you come to do some mode programming where you match the mixture knob orientation with the program knob. They were out of sync, so I was programming 90 degrees richer than intended each time. I realigned the mixture knob, reloaded you're defaults, copied them to B and started to make some progress.
 
Thanks for the help everyone.
Regards,
John (back to taxi testing)
 
 
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster