Sounds like the tempII sensor to me... (or the associated wiring or grounds).

It sounds like the ECU is paying attention to the O2 sensor before it has
heated up enough to function properly.

At 01:48 PM 5/3/2006 -0700, Zoltan wrote:
>Hi guys,
>My car won't idle when cold, almost at all.  But if I press the gas and
>keep it running about 2000 rpm for about a half minute, it will idle.  And
>as it gets warmer, it idles a little higher, but not higher than 900.
>What is to look at?
>Zoltan