Mailing List flyrotary@lancaironline.net Message #46902
From: Mike Wills <rv-4mike@cox.net>
Subject: Re: [FlyRotary] Re: Ignition Check?? Re: frustrating couple of days
Date: Sat, 4 Jul 2009 19:10:35 -0700
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Just to address the issue of remoting the switches. My PCM is located in a center console just in front of the stick and about 6 inches behind the EC2. The switches are located in the bottom of the instrument panel just above the console. So I have a run of about 18" of wire from the PCM to the switches and about 6 - 8 inches from the PCM to the EC2.
 
If I had mounted the PCM in a conventional location like center of the instrument panel I'd have had a wire run of about 2'. In other words, looks to me like the end result is about the same amount of potential antenna either way.
 
Mike
----- Original Message -----
Sent: Saturday, July 04, 2009 9:50 AM
Subject: [FlyRotary] Re: Ignition Check?? Re: frustrating couple of days

Ok, Mike

 

Yes, it does.  I just wanted to check and make certain there was no correlation between your ignition check and corruptions and was not certain you were or were not performing the ignition check.

 

Adding a small capacitor if a fairly inexpensive ($$ and Time)  attempt at a fix {:>).  Since it sounds like you are 99.99% it is not a wiring or loose pin problem, that leaves two or three possibilities;

 

  1. The wire used to remove the switches does add a larger “antenna”  length to the switches – which would enhance noise reception/
  2. The switch debounce may be effected by remoting which might make problem 1. even worst (if it exists)
  3. Some problem inside the EC2

 

The 0.01 ufd cap could affect either condition 1 or 2 – so will be interested in hearing the results

 

Good Luck

 

Ed

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills
Sent: Saturday, July 04, 2009 11:38 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Ignition Check?? Re: frustrating couple of days

 

Ed,

 

I was not clear in my description of when the problem seems to be occuring. So to clarify:

 

 In my normal tuning of the EC2 I never mess with the B controller. And have never noted a problem with corruption of EC2 data. When I began flight testing back in February thats when the problem began to occur. After 3 instances I stopped flying.

 

 I decided it was about time to resume flight test last weekend after 4 months of mods and ground running without any problems. On saturday I flipped to the B controller just to see if it was OK and the engine died. This was not immediately preceeding a planned flight and I did not perform an ignition check. Over the course of the weekend I had a total of 4 cases of corrupt data. Three times there was an undefined problem on B that prevented the engine from running and one case where the A staging point got corrupted. The ONLY difference between these 4 cases of failure and the previous 4 months of failure free testing was the selection of the B controller. I never tested the ignition.

 

 These 4 failures occured over the course of approximately 25 engine starts and a total run time of about 2.5 hours this past weekend. For each engine start I toggled back and forth between A and B multiple times at various RPM settings. I estimate around 100 operations of the A/B switch resulting in 4 failures. The definition of intermittent.

 

Does this clarify? BTW, I am going to take your advice and add a .01uf cap on the A/B input. What have I got to lose at this point?

 

Thanks,

 

Mike

----- Original Message -----

From: Ed Anderson

Sent: Friday, July 03, 2009 8:39 PM

Subject: [FlyRotary] Ignition Check?? Re: frustrating couple of days

 

Mike,

 

I could not help but wonder that when you were  unsuccessfully attempting to replicate you B controller problem by switching back and forth - did you also try your ignition check while in B?   You mentioned that you normally made an ignition check with controller B on in preparation for flight.  However, you did not indicate that you were making such a check when you were trying to duplicate the problem.  

 

IF you did not, then I would suggest that you again try to duplicate the problem by switching from A to B, but include the ignition check while in B.  Do it a few times and see whether or not B gets corrupted.

 

Ed

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills
Sent: Friday, July 03, 2009 10:59 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: frustrating couple of days

 

Steve,

 

My staging point is set at 18" which ends up being around 3300RPM. So far I still havent been able to prove for certain that the corruption is linked to switching A > B, much less determine that it only happens above or below the staging point.

 

All 4 of my injectors are the same - checked them all with an ohmmeter. They are all of the type that does not require an external resistor.

 

Mike

----- Original Message -----

From: Steven Boese

Sent: Friday, July 03, 2009 9:13 AM

Subject: [FlyRotary] Re: frustrating couple of days

 

Mike,

 

Is 3000 rpm above your staging point?  If the corruption of the controller only happens when changing from A to B above the staging point, check to see if one or both secondary injectors have lower resistance than specified.

 

Steve Boese

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills
Sent: Friday, July 03, 2009 9:50 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: frustrating couple of days

 

Dave,

 

Thanks for the offer and the input. Swapping my EC into your plane would be a desperation last move due to all of the hassles involved. And as you say would not necessarily prove anything.

 

I said it happens when I'm preparing to fly, but that isnt entirely accurate. It would be more accurate to say that in the past it has happened only when I have switched to the back-up controller which usually occurs in prep for flight. This past weekend I had fired it up and taxied down to EAA for lunch. After lunch I taxied back to my hangar and prior to shutting down I ran the engine up to about 3000 RPM and switched to the B controller. The engine died and I had to copy the A program to B to get it to run on B. Switching to B was the only pre takeoff checklist item I performed.

 

I think about the only thing you hit on here that might be related is heat. But hard to say without more instances of failure and a way to link cause and effect. On saturday when the engine quit on B the engine was completely cowled. On sunday when I had the second instance of an engine quitting on B, the upper cowl was off but the lower was on. When the staging point was lost the upper was off, lower on. Yesterday when the engine quit on the first attempt at switching to B the engine was completely uncowled. Maybe I'll run it up a few more times today uncowled and if it works OK, try putting the cowl back on and see if I can induce failure. Doesnt seem likely though that anything under cowl could cause this sort of problem.

 

This may all have to wait until Tracy weighs in with his opinion. I'm not inclined to make drastic changes until I hear from him.

 

Thanks,

 

Mike 



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