When you say your engine will not idle below 2000 rpm; is that at start-up
or when the engine is fully warmed up? I would be reluctant to cite the
head temp sensor as fault of poor idle at any time. The more likley
culprit would be a faulty air regulator or some type of vacuum leak or
even poor idle adjustment. Does any one know the temperature at which the
sensor "activates" the CPU to enrich the mixture? FWIW I had a head temp
gauge attached to the same point at the head temp sensor and the readings
were in the 250 to 300 range. Moving the head temp gauge to the no. 3 plug
increased the reading 50 degrees F (normal 350 F); so there appears to be
a fairly broad range of temps even on the head itself. This would lead me
to conclude that it would take a fairly extreme temperature to induce the
head temp sensor to cause the aformentioned problem, perhaps even in
the range of 400 plus. DC

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David Carment
School of International Affairs
Carleton University
Ottawa, Ontario
K1S 5B6
voice - (613) 788-2600-6662
fax - (613) 788-2889
Email address: dcarment@ccs.carleton.ca
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