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Hi Guys,
Today I taxied out to test the mods made to my cooling system and ran right
into a new and unanticipated problem.
During the normal pre-take off engine checks, I selected "B" computer and
then went to the coil disable switch. Pressing the switch in one direction
produced zero change, but the other choice produced a very noticeable
SILENCE. Duh? Never had that one before. Taxi back. Temperatures stayed
around 170 during this 15-20 minutes of ground running with OAT <75*
It was easy to isolate the faulty Leading coil as the culprit. I talked to
TC who gave me the resistance values to check out 1. the resistor, 2. the
coil, and a diagnostic procedure. Thanks, T!
Leading coil resistor and coil tested okay.
Next we checked to make sure the EC2 was functioning okay by running a plug
wire to an extra plug clamped to the top of the block. Fire on both A and B
for the leading coil. Double Duh!
Ran the engine again and the same thing happened again. Disabling the
Leading coil in "B" again shut the engine down.. Called TC again.
Tracy suggested that it might be a plug problem. Triple Duh?! We changed
the leading plugs with plugs that had been cleaned with glass bead blasting
but were not new. The old plugs only had a couple of hours and looked okay.
No wear visible. A little carbon. Insulator clean.
Cranked her up and after adjusting mixtures on both A & B for about 2600 rpm
we test the coils.. No Problem. a little more rpm drop on B, but
nothing major.
Now, here are the pestering nagging questions: Why would relatively new
plugs fail when given the total load? Why would both plugs fail at the same
time? Is there something going on that is being overlooked? Has anybody
else ever seen this happen? (Ed/ Eddie, are you there?) Did this happen
because I'm so close to 2R4?
Be easy, guys
Tommy James<><
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