Coolant temperature sensor question.

[Huw Powell]

> For the NTC sensor, A higher ohm value makes the car run richer. (Try
> unplugging the connector when the motor is cold! Try it when it's hot, and
> it'll almost die, it runs so rich).
> As long as the sensor is a high value when cold (value not all that
> critical), cold starting should be OK. However, you want the hot value to
> be of correct, so that the mixture is not running way too rich all the time.
> ( I just had mine out recently, and got about 3000 ohms cold, and around
> 250 ohms under the hottest  water from my kitchen tap)

Yup, at some certain low resistance, the ECu simply switches into closed
loop and lets the air cone and OXS regulate the mixture.

when cold it is nice to have it be close enough that the ECU sets the
appropriate enrichment - but as you say, so long as the resistance is
high, it will probably start ok.  If it doesn't drop it will keep it
rich and waste a lot of fuel, and i think this is also bad for your OXS
and cat.

-- 
Huw Powell

http://www.humanspeakers.com

http://www.humanthoughts.org