Also, I’d expect turning off the primary would then result in a leaner mixture 

 

Absolutely agree with this.  

  

Yes, we tested the individual injector banks a number of times and had no problems.  Although; I can’t say for sure that we did it below the stage point.  

 

The engine is amazingly tolerant of mixture changes at higher power settings, so it would be important to know it worked on the dyno at the same power settings you're testing now. 

 

You’ve got me thinking that I did have to take the pins out of one side of the plugs to pull them through to the engine compartment.  The plugs are marked A, B, C, and D. and the wires were marked to match.  I, of course, got them back in correctly, right?  I’ll have to check. 

 

That's the idea.  The prime suspect is anything that could possibly have been changed between the dyno and the plane.  The second suspect would be something appeared to work properly on the dyno, but wasn't tested thoroughly enough to be sure.  

 

Another note about checking these connections.  It's VERY easy to overlook the same mistake multiple times, particularly if you're convinced it's OK.  It's just a little practical joke that our brain plays on us.  Everyone does it at some point.  Ever spend 20 minutes looking for something that you eventually "find" right on the desk in front of you.  No?  Yeah, me neither :-)   If possible, have someone else double check these connections just to get an unbiased view.

   

Thank you for giving this so much thought.  It is appreciated. 

 

You're welcome.  Good luck.

 

Rusty (hoping John isn't facing East and still blowing my direction)