I put about 4 - 5 hours of time on my engine installation months ago, and had everything pretty much “dialed in” for proper running from 1000 rpm up to max static rpm (~5200).  Then it sat with no running for about 6 months while I did upholstery, paint and other stuff in my life.  I’ve moved the plane to the airport, and got it all assembled.  Yesterday rolled it out for an engine run-up.

 

Since the beginning it had always fired off after a few strokes, and I’d turn off the cold start switch seconds after it was running. This time I had difficulty in getting it started.  Once I got it running, it would quit immediately when the cold start switch was turned off.  Leaving the cold start “on” it runs fine above about 2000 rpm with the mixture turned toward lean to about 9:00 o’clock.  Reducing rpm lower it wants to die. As I increase rpm above 2000 I need to rotate mixture knob significantly toward to richer to keep things smooth.

 

Fuel pressure, MAP, ignition, etc. all are normal.  When I get the mixture knob adjusted it is smooth, so injectors are working on all three rotors.  I didn’t take it above the staging point so it is running on one set of injectors.  Haven’t had a chance yet to look at the mixture map on the EM2, and won’t get back to the airport until Monday.

 

I’m a bit baffled on what could have changed since last operation and what to check.  Anybody have any similar experience?  Ideas?

 

Al