lol, I was taking more generic things, but since you asked...
could be the WTS (Water temp sensor)
this signals an enrichment to the ecu during warm up, problems with the sensor can cause the issue you describe.
there are 2 possible types of sensor - NTC or PTC (Negative temperature coefficient or Positive temperature coefficient. on an NTC the sensor should read 1.5 to 2.2 volts at an ambient temp of 20 degrees (Water temp) - when the water temp is apx 80-100 degrees c, the reading should be 0.1 to 0.2
on a PTC sensor, the voltage at ambient should read .5v at ambient and 1.2 volts at over 80 degrees c.
the idle control valve fitted to the multipoint injection by RENIX is either a 2 wire or 3 wire device.
It works by the ECU pulsing it to open or close bypassing air from the outer side of the throttle plate to compensate for warm up and engine load (ie headlights)
the 2 wire will fail safe if it dies, the 3 wire will just end up where it was
Best bet is the WTS.
also, check for induction leaks as this can cause a similar problems.
Joe