UrQ Cold Driving Problem

[ANDREW FINNEY <afinney@bigplanet.com>]

This problem has plagued me since owning the UrQ, or was it since having
it chipped by TAP? When I start the UrQ it starts right up but requires
a couple of very light taps on the throttle, light enough to not blip
the engine, to keep running. Once started it runs perfectly even in the
coldest weather until approximately 3 minutes after starting, at which
point it idles very roughly and will stall if I don't raise the idle
speed a little.  This happens with a hot or cold engine, but occurs more
rapidly with a hot engine that has sat for more than 15 minutes. It does
not happen to a hot engine that has sat less than 15 minutes.

When I look at the duty cycle, the problem occurs right as the car goes
into open loop (OX is working). After a few more minutes of behaving
like this, it drives and idles fine but I always come to a stop light at
the bottom of my hill in the morning right at the problem time and it's
a PITA. The car backfires or pops lightly when decelerating during this
period (I have a very open exhaust, sleeved kitty, etc so it's always a
little more noisy on decel) The duty cycle goes from the preset value to
jumping around in the 90's and when it settles into a good idle again
it's near 50% and jumping around like it should. RDH told me that the
UrQ has too short of a warmup period, but how do I correct this problem?
Should I set the idle speed to the correct value, tune up the car and
then raise the idle speed to 1000 rpm? Please help, I can't stand this
problem.

Andrew Finney
1983 UrQ.