OK here is what happens when you start out with both primary and secondary “disable” switches ON – providing power to both sets of injectors.

When the EC2/3 is operating below the staging point, then normally the EC2 grounding/activation   “pulse” is sent only to the primary injectors.  Once you increase manifold pressure past the staging point, the EC2 halves the pulse duration and activates  the secondary injectors thereby doubling the number of injectors but cutting their fuel flow in half.   So your fuel flow is the same (or should be ) both sides of the staging point immediately upon staging.  The EC2 has  doubled the number of injectors turned on - but halved their fuel flow leaving you with the same fuel flow both sides of the staging point (ideally {:>)). Did I just repeat myself?

 Another way of looking at it, is when below the staging point (idle low rpm)  the number of injectors are reduced from 4 to 2 (except for the three rotor guys, of course).  So  the EC2 then doubles the on-time duration to the remaining two active injectors to make up for the reduction in the number of injectors from 4 to 2.  (Doubling the on-time duration is also something the cold start function also  does – test on this later).

So lets take you back below the staging point, you are operating on the primary injectors.  You decide to turn off the primary injectors (leaving the secondary injectors on).  When you turn off either set of injectors using the “disable” switch,  you are also triggering  the “Cold Start” function by grounding it (provided once again you wired it as Tracy recommended)

With the cold start function activated, the EC2 will attempt to ground (activate) both pairs of injectors (whether they have power or not) as well as doubling the “pluse” duration.  Since there is no power to the primary injectors (you turned them off - remember), the primary injectors can not squirt any fuel in – but, since the secondary injectors can and do - they continue to provide power to the engine even below the staging point.   Recall the cold start function also doubles the pulse width at the same time.   That is at least part of the reason why staging can be somewhat more difficult to sort out if your primary and secondary injectors have a large different in flow rate.  This ALL assumes you have wired the injectors as Tracy specifies.

Now if both primary and secondary injectors both have power  and you turn on the cold start switch on the control panel – then the EC2 will double the on-time for both pari and you can very quickly flood your engine.  So DON”T do that!

It can get confusing for us mortals, but fortunately the EC2 always remembers.

Hope this helps

 

Ed

 

 

 

 

Ed Anderson

Rv-6A N494BW Rotary Powered

Matthews, NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.rotaryaviation.com/Rotorhead%20Truth.htm

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Jeff Whaley
Sent: Tuesday, June 30, 2009 12:10 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Below staging ... was Re: More progress, more questions....