Michael,
First thing I would do is check the TEMPII sensor. That can be easily done
by removing the ECU plug and comparing the resistances of Pin 10 (TEMPII
sensor) with pin 9 (TEMPI sensor). Use pin 6 as common reference (ground).
This must be accomplished before the vehicle has been driven i.e. the engine
is at ambient temperature. That way the TEMPI sensor will be at the same
temperature as the TEMPII sensor, and hence at the same resistance. I would
expect them to be within 5% of each other.
Ken Lewis
http://neksiwel.20m.com/