flyrotary@lancaironline.net Mailing List Archive

Thanks Mark, I have the diodes at the sol. both start & master. From reading yours & other posts I would have to say V-spike is the problem cause, after thinking about anything diff. from 10 hrs. of air time prev. I came up with the landing & taxi lights were on this last flight. Now, I did not switch them on in the air, I switched them on when still on the ground with aprox. 22 min. running on the ground then flew for aprox. 15 min. before fuel map corruption. Will look into the routing of circuits for both lights. David

From: "Mark Steitle" <msteitle@gmail.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Thursday, August 22, 2013 6:00:11 AM
Subject: [FlyRotary] Re: Fuel map scrambled.

David,

I chased a similar problem on my 3-rotor back when it was barely out of initial flight testing. Tried a lot of things, but nothing seemed to fix the random re-set of the EC-2 MAP table. Someplace I heard about voltage spikes originating from the starter solenoid. I installed a large diode across the "+" terminal of the starter solenoid and haven't had a problem since. The culprit may be different with your a/c, but I would be very suspicious of anything that could generate voltage spikes. Also, check all of your grounds thoroughly.

Good Luck,

Mark S.

P.S. The first thing Tracy always asks is, "Did you try the B-controller?" How does the B-controller MAP look?

On Wed, Aug 21, 2013 at 9:09 PM, <hoursaway1@comcast.net> wrote:

1st..... am now on the ground safe & sound, no damage normal landing. The story goes....... Level at 2500' above Mason Jewett Field, ( hazy evening, aprox. 7:30 pm ) on the down wind abeam of the end of the runway, 4600 rpm, ? MAP, 125 MPH ind., 3rd circle around the patch getting ready to put in full cruise pitch on prop to do a full throttle numbers gathering. Then the eng. started running very poorly, missing, stumbling hard, destict loss of power, tryed to descend & come around to land but am high & hot with ( RV's need air brakes ) eng. smoothed out, chose a sweet spot & climbed out to go around,,, low but climbing, ran smooth 4000 rpm, landed ok. Before shutdown, checked fuel map bars for EC2 on EM2, some in the middle some at the bottom,,,Lean,,, why did the fuel map scramble suddenly, steady cruise flight, made no changes at that time? At the airport by 6:30, pull plane from hanger to do two tests tonight, 1st. run eng. at low power/idle like sitting in line for takeoff from Osh or ?, how long can we stay running without getting to hot, 18 min. coolant 205 F, oil 175 F, ok that's good enough for me lets go fly & do the prop full cruise pitch test run. That was the start of the evening, ended differently than I would have liked. But nothing bent. Did not reset EC2 yet, am going to start eng. & check to see if computer B runs ok, did not get a chance to throw that switch, when I found the sweet spot I changed nothing, just came around & landed. What is the fix for this anomaly?? David R Cook RV6A Rotary