Mailing List flyrotary@lancaironline.net Message #35025
From: Tracy Crook <lors01@msn.com>
Subject: Re: [FlyRotary] Re: EC2 mixture changes
Date: Sun, 31 Dec 2006 12:36:24 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>

Buly,

Since you said you got a curve in the MAP table after resetting the table, I assume you did the reset with the cold start switch up (on).   This loads the MAP table from my engine which may or may not work for you.  If the cold start switch is down,  resetting the map table clears it to a flat line at mid scale which is the normal starting point for tuning the engine if the curve from my engine does not work well on your installation.

 

Now the confusing part.  You may not have had the cold start switch up but if you had the injector switches off, they also activate the cold start switch input to the EC2. 

 

Even more confusing, if your injector switches connect to +12 even when the EC2 power is off, turning them on will provide power to the EC2 through the injector lines.  Explanation of why is too long to go through so just accept this fact.   This will prevent you from resetting the MAP table at the time and way that you expect.

 

So, in order to get the expected results when doing a reset (on any EC2 Mode)  always have the injector switches on BUT make sure you master switch is OFF,  THEN turn the EC2 power on.  You will now (presumably ) still not have power to the EC2 or injectors if your master switch is REALLY a master switch.     Now you are ready to do the reset.  Select the appropriate switches & modes explained in the instructions and then turn the master switch ON.   Now the EC2 will have done the expected reset function.

 

Note that the MAP table at the low rpm range (0 – 63) is  normally flat  after the staging point or the point at which the engine is running above the low rpm threshold (about 3000 rpm).  This is because you never really use this portion of the MAP table so it is not surprising that your engine ran relatively OK.   Above this threshold, the EC2 switches to the high rpm table (64 – 127).  Did you scroll ll the way through all map table addresses (0 - 127)?  You should have seen the curve resume somewhere in the upper range between 64 and 127).

 

To properly understand what you are seeing in the MAP table and what it means, there is no escape from having to read and understand the theory of operation in the installation and setup guide.  Sorry, reading that dry, boring stuff is part of the price you pay for running an alternative engine.

 

Tracy

----- Original Message -----
Sent: Saturday, December 30, 2006 8:09 PM
Subject: [FlyRotary] Re: EC2 mixture changes

Hi Tracy and Al,
Today I looked at the MAP table. At the beginning there 3-4 bars 
going up from zero to 50% up after that all the way to the end there 
was nothing.
Just flat line with no bars going up and down. Reset the factory 
settings and now I have the curves on the MAP window display the way 
they are supposed to look like. Did not have time to run the engine. 
I'm surprised it run at all :)
Buly

BulyOn Dec 29, 2006, at 12:23 PM, Tracy Crook wrote:
> Good suggestion from Al,  Buly.  I can't remember, do you have an 
> EM2?  If so, check the MAP table with the EM2 and get familiar with 
> what the correction curves look like for your engine (no two are 
> exactly alike).  Good idea to check it periodically for any signs 
> of data corruption if you think something is amiss. So far, Al's 
> controller is the only one that I know of that has had this 
> problem.  Not unit specific because it has happened on 3 different 
> EC2s in Al's plane so I have concluded that it is something unique 
> to his installation.   I'd like to get to the bottom of it and any 
> other reports would be helpful.
>
> Al and two other composite aircraft have reported mixture changes 
> when transmitting on the radio.  Sometimes the problem is frequency 
> specific.  I have identified a fix for this and it should be 
> implemented on any EC2 that exhibits this problem.  A .1 uF 
> capacitor is added directly across pins 1 and 2 of the A controller 
> MAP sensor to eliminate this problem (B controller is not 
> affected).    RFI problems are a bitch to find sometimes.  There is 
> already a capacitor across these two pins on both A & B 
> controllers.  The one on A is only a couple of inches away from the 
> sensor on the circuit board but that makes all the difference.  The 
> part must be physically close to the sensor to eliminate this RFI 
> problem.  All future EC2s will have this added capacitor installed.
>
> You can experience odd changes in the EC2 behavior for several 
> other reasons.  For example,  I have to change the mixture control 
> from the normal position when I do a hot start and take off 
> because  the air temp sensor has been heat-soaked from heat in the 
> engine room.   As it cools off on takeoff, the mixture gets richer 
> and I then return the mixture control to it's normal position.
>
> Tracy (autopilot installation hell almost over)
>
>
> ----- Original Message -----
> From: Al Gietzen
> To: Rotary motors in aircraft
> Sent: Friday, December 29, 2006 9:58 AM
> Subject: [FlyRotary] Re: Yet another non-event story
>
> > >I noticed my mixture bar was going from lean to totally
> > desapearing. Turning the knob to full rich was not enough.
> > I saw this a few times.
>
> Buly;
>
> It would be interesting to know if you had it previously tuned 
> giving you
> correct mixture.  I have had on-going problems with spurious 
> changes to
> settings in the EC2.  Carefully tune it one day, and find things have
> changed the next, and have had tuning changes occur during flight.  
> I have
> noted changes in the mixture table, stage point setting, injector 
> pulse
> width. Many, many hours spent trying to determine cause, but as yet no
> explanation.  It has been assumed that it is specific to my 
> installation -
> composite pusher with EC control box at the firewall, EM2 
> acquisition module
> at the firewall, display on the panel.  The problem is primarily with
> controller A which communicates with the EM2.
>
> This may not be relevant to your installation, but it would be 
> worth paying
> close attention to getting it tuned correctly, and see if it stays 
> that way.
>
> Al
>
>
> --
> Homepage:  http://www.flyrotary.com/
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