Al,
Do you have an EM-2 so that you can see how your injector map is set?  Personally, I feel for the guys that are trying to tune their engines without it.  I had to change my map settings to about -100 steps in order to get my n/a 3-rotor to run smoothly with the mixture knob in the 12 o'clock position.  I was really surprised that I had to change it that much, but it sorta makes sense because I'm using 550cc injectors.  More tuning to do once I get a prop installed. 

Mark S.

   At 08:34 PM 9/23/2004 -0700, you wrote:

Maybe I can get some help on this one.

 

Engine running quite smoothly at 2000 rpm, warmed up.  The mixture setting about 4:00 5:00 o clock position, which has seemed odd to me that it need be way over there using the default MAP table, but that was where it ran the smoothest.  Manifold pressure on EM2  reading about 10 (This seems a bit low, but that s another matter); in any case, below the injector staging point.

 

Switching off the secondary injectors results in very rough running; much too rich, turning mixture back to about 11:00 gets it smoothed out.

 

Turning off the primary injector switch results in engine faltering badly, almost as though it s running on only one of 3 rotors, changing mixture doesn t seem to help, engine will die on 4-5 seconds.  At restart with both sets on, the mixture has to be set back to lean for a bit for the engine to clear, and then runs fine again at the 4-5 o clock position.  Suggests that turning primary off makes mixture way too rich, or whatever.

 

Double checked all connections, switches, staging relay all seems fine.  This is the same wiring harness that worked fine on the dyno, so with all the connections where they belong one would expect it to work again.  This is the first time since on the plane that I ve experimented with disabling injectors.  I did this briefly the first time I started, when the engine was cold, and had noted that it got rough turning off the secondary, and died turning off the primary, but didn t address it further at that time, and forgot about it since (or I ve been in denial about it).

 

I can t seem to come up with a scenario that fits this picture.

 

Switching to controller B resulted in similar behavior, but rougher running, likely because it takes MAP reading from one runner only, and I have no pulse filter on that connection.

 

Somewhere in all that I noted that even when running smoothly, the mixture bar graph on EM2 was not steady; going up and down roughly around the midpoint.

 

The worst part is that the rich running put a light coating of black soot on my beautiful white propJ.  (Pusher, exhaust goes through prop).

 

Al