Ok.. are the "programs" you have saved the same between A and B? If they are, then lets focus on what the difference is between the A side and B side.. You have the manuals now, I dont, but I want to say that the A side has some sensor inputs that the B side doesnt.

Given that you claim that it got rough at the same instant you threw on the lights (strobes), did you turn off the lights while running A side to see if it cleared?

Without looking at things as they are currently, but from memory, I want to say you have the EC2 on the pilot side aft firewall, and the strobe box somewhere on the pax side firewall/against the spar, with the shielded strobe wires running along the spar to the wingtips...

What I am getting at is.. strobes are noisy from an electronics standpoint. The A side controller uses additional sensor inputs that the B side doesnt (if I remember right). If there are grounding issues, or if the strobe wires cross too close to certain EC2 wires, they can cause interference. The A side may be more sensitive to that noise.

Strobe wires should absolutely not be bundled with signal lines/control wires, and if they have to cross paths, cross at a 90 degree angle.

Grounding is paramount to everything working right in an ECU controlled engine. And.. with a composite airframe, its even more imperative to be meticulous about grounding. There should be one and ONLY one path to ground from any component on the airplane. I dont remember if you have a grounding block on the aft firewall under the cowl, but this was one of the reasons I ran the big ass heavy groundwire from the battery in the nose to the back end of your bird.

I'm 90 percent sure that whatever issue you are having is tied to either strobe noise jacking with the engine controller, or some ground somewhere being intermittent, or ground-looped, or a shielded wire not shielded properly.

Good luck!
Dave

On 10/26/2010 8:50 AM, Chris Barber wrote:

Since my oil pressure was down a bit following my pressure repair I decided to take heed or some of the comments regarding one of the possible causes as presented here.  It seemed to be the easiest that I could try.

 

So, I shelled out the bucks for some Royal Purple 50 (actually, 20/50 IIRC).  Geezh, I thought the 30 weight and 40 weight was pricey at $8 and $10 a quart, this stuff was $16.00 a quart.  I drained about 2 to 3 quarts out of the pan and out of the filter and replaced it with the 50 wieght.  So, now it was a blend of the 30 and the 50.  I cranked up the engine and my oil pressure was up by about 10-15 psi.  WOW!  I did not expect such a dramatic increase.  I had just run the engine earlier (before I went and purched the oil).  Before the change, my idle pressure was around 28-30.  After the change it was in the low 40's.  The most psi I was getting  before the change was about 50-55 psi at 6300 rpm.  After the change it was at about 72 psi at 6300. 

 

I let her idle for about ten minutes and all seemed good. So, since my temps seemed good and steady now that Outside air Temps were have now dipped down into the low 90 I decided to taxi around a bit.  Yep, I sometimes enjoy taxiing around in my very expensive go-cart. 

 

The engine was running sooooo smooth and strong.  I was feeling pretty damn good about it all.  Since I was moving around on the ramp where there was quite a bit of traffic following this weekends big 'ol Wings Over Houston air show, I reached down and switched on my nav/strobe lights.  At the exact instant of turning on the light (which, btw, are on my secondary alternator circuit) the engine started faltering and wanting to stall out.  WTF!!!  I switched to the B computer and things smoothed out.  Back to A and had to add throttle and mixture to keep it running and it was still rough.  Back to B to make it  back to the hangar.

 

Once back at the hangar, I checked the MAP table (RWS EM2, btw) and nothing seemed changed from earlier.  Kinda sounded like fuel was having trouble getting to the injectors.  I would think to look at the injectors first, but am not inclined to focus here too much since the engien smoothed out when changed to the B computer.  Since both computers use the same systems, it seems to be isolated to the primary computer.  Please, correct what I am missing here.  Since my judgment was clouded with anger, I put everything back in th hangar for the night.  This good good bad good bad stuff is taxing and discouraging.  I feel I am so close, then this nonsense.  (on top of my RPM's cutting out around 6000 rpm - can slowly inch it up to 6300, with power to spare- if I go slowly, but cuts out at rpm over 6300 and change on the EM2 and an EGT reading issue). To quote Mork....."Heavy sigh".

 

Trying to wrap my head around where to start on this latest PITA gremlin.  It had been running as close to perfect as I could have imagined.

 

All the best,

 

Chris Barber

Houston