The Renesis CAS was brand new.  Unlike the older style CAS, the Renesis CAS has only 2 wires (shielded).  They go directly to the EC-2 via the D-sub connector.  The shield is grounded to the EC-2 case.  This was not the problem.  In fact, the problem wasn't caused by wiring at all.  Good guess though.   

 

Mark

 

On 9/14/07, cbeazley <cbeazley@innovista.net> wrote:

>
> OK guys, here's one to think about.
>
> Problem:  Major mis-fire at 6600 - 7000 rpm.  Engine runs great up
> until it begins mis-firing.  This is a 20B running an EC-2 that's been
> updated with the latest s/w (as of 9/1/07).  This includes the snubber
> fix and a modification for the Renesis CAS.  Before the snubber
> upgrade, the engine ran good in the upper rpm range, but not in the
> lower rpm range.  After the snubber upgrade & Renesis CAS
> modification, it ran great in the lower rpm range, but had a
> serious mis-fire beginning around 3800 rpm.  An attempt was made to
> correct the mis-firing problem by installing a resistor/zener diode
> circuit in the CAS lead (this strategy worked for another Renesis
> flyer).  This approach was partially successful, but only up to the
> mid 6K range.
>
> Multiple phone calls to Tracy resulted in no fix.  I think he's hiding
> in Colorado so he won't have to take my calls. (I'm kidding, of course.)
>
> Finally, today (after months of struggling) I discovered what was
> causing the problem.  It now runs great up to 7300 rpm, verified by a
> full-power run down the runway.  Anyone want to guess as to what the
> problem turned out to be?
>
> Mark S.

CAS shielding/grounding?

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