rough idle when cold

[djnolan]

Originally Posted by Tom944

Sounds like the heater in the O2 sensor has failed. Initial 30 seconds is open loop then it requires the heater until the sensor warms up. Once warm the heater is not required. Change the O2 sensor.

I will do a little detective work with the Ohm meter and see what I find. Thanks!

[djnolan]

The O2 Sensor heater checked out OK with an Ohm meter.

[OK-944]

To add my two cents...I just rehabbed my ICV and my 85.5 now starts up and idles great. When I took the ICV apart, I was a bit amazed and distressed at how worn out the commutator spindle and brushes were. I cleaned the commutator spindle up as best I could...and bent the brushes inward - and now all seems well.