ur-q mixture problems

[glen powell <gpowell@acacianet.com>]

I'm having problems with the A/F mixture on the KUQEFH.

After the engine fully warms up, about 20-30 minutes, it appears
that the CIS goes open-loop. The mixture can go too lean or too
rich and the FWO enrichment can fail to kick in. This is all based
on observing the HalMeter A/F display. Right now I suspect a faulty
but new O2 sensor or mebbe the warm-up regulator.

Anyone know what 'tells' the computer that the engine is warm and
can go into closed-loop operation?

Any ideas or thoughts on what could be causing this flaky mixture prollum?

Please respond directly to:  gpowell@acacianet.com

THANKS!

-glen