Volks,
  My 1990 GL is doing weird things on startup.  Occasionally when I turn
the key, the engine catches instantaneously (no cranking at all) and
idles like crap -- the timing is way, way off -- for about ten seconds.
Then, like magic, all cylinders fire in order and the engine purrs like
the day it rolled off the assembly line.  No other problems once the
engine settles down.

  Because the badly-timed idle always lasts for the same length of time,
is the ECU trying to tell me something?  I cleaned the ground on the ECU
and the engine not too long ago, but I'll do it again this weekend.

  Anyone have a guess as to the culprit?

Best,
d.