In a more refined engine control system, the fuel would not be cut off when
coolant is below a set temperature (say 160F). But Digifant is relatively
primitive, and these no load conditions are really bad for it.

I have the same problem going down Little Cottonwood Canyon, 8-10% grade for
9 miles. My solution is to coast/idle for a minute, then put it in gear and
decelerate for a minute, rinse repeat. During the deceleration period the
higher RPMs moves the heat thru the heater system because of the RPMs. This
keeps enough heat in the coolant to keep occupants from freezing, and
doesn't overheat the brakes.

John
Aircooled.Net Inc.