[Beav]

Backprobing (with straight pin - my preference is 'T'-headed mattress pins but any stout, thin pin will work) the sensor connector while connected to the sensor with the key on, engine off (KOEO.) Since your problem, if I recall correctly just occurs for around five minutes at a time it sounds as though the engine temp sensor would be bad but it could also be most anything that is going through a warm-up situation. The symptoms point to a/f ratio problem. I need to read back through again but I have a busy schedule today. I'll try to pick back up later tonight.