Steve,

 (assuming you are using the EC2 AND that you are using a proper 3 port fuel pressure regulator which adjusts pressure with manifold pressure)  I also assume you are saying that mixture is too rich even though the mixture control is at leanest setting?

 

If you have already adjusted the mixture as lean as possible at low throttle using Mode 1 or 9, you need to do the following:

On the ground with airplane restrained, run engine at about 25" Hg MAP.  In Mode 3, LEAN the mixture about 3 - 4 steps.

Go to low throttle where you were too rich and see if mixture can be made right using Mode 1 or 9.  If not, go back to MODE 3 and adjust leaner a couple of steps.

 

Repeat until you can get mixture in proper range at low throttle.  

 

After doing this, you may find that mixture is too lean at higher throttle settings.  If so, adjust richer where needed using Mode 1 or 9.

 

Make sure you know exactly how the different Modes work.  They are not the same.  See instructions for details.

 

Change injectors and other hardware only after you are sure the problem can't be solved by adjustments.

 

Tracy  (working on automatic program mode for EC2)