I'd vote for Noble's first suggestion about some kind of physical break
in the wires or connection with the DME/KLR plug.

An easy test is to use a multimeter on the continuity setting and with
a friend trace the wires (there aren't that many, and they go directly
to the engine sensors -- like throttle body, mass air flow sensor,
magnetic sensors, etc.)

I would also make sure your RPM and TDC sensors didn't get bumped or
damaged while you were fussing with the WG.  Or, more specifically, the
wires.  If these are not giving a signal to the DME, she won't start --
no matter what.

I was also thinking, if you put the covers on the ECUs incorrectly, you
might have some grounding problem that only started once you screwed
the ECUs to the mounting bracket -- as opposed to leaving them on the
carpet.

Overall, I've found those computers to be pretty durable, so I'd say
chances are something much simpler (but perhaps harder to find) has
gone wrong.

Good luck!

p.s. re-reading my post here, I want to give more emphasis to the RPM
and TDC sensors -- these are specifically what the DME uses to decide
if or when to fire a spark plug; and the airflow/temp/knock/boost
sensors control the duration of the pulses to the fuel injectors (as
well as spark timing to optimize combustion at different RPMs) --
however, most of these have a "fail safe" or "default" value in the
computer which will still enable the car to run if one of those sensors
goes bad.  This is not the case with the RPM and TDC sensors...  The
ECU must get signals from them before it even considers starting the
engine.