ICQ>

Mike,

The original Volvo tech manual for the B23F engine with the Bosch LH-Jetronicc II fuel system says to test the temp sensor as follows:

1. Switch OFF ignition.

2. Remove panel forward of right front door to gain access to the control unit.

3. Release catch and remove connector from control unit.

4. Remove connector cover. Only check terminals from the side of the connector. Do not probe the terminals in front, where they connect to the control unit as they can be easily damaged.

5. Connect ohm meter between chassis ground and the side of terminal 2.

6. The resistance should be as follows as various temperatures.

175 deg F = 290-364 ohms

68 deg F = 2280-2720 ohms

14 deg F = 8,260-10,560 ohms

Zero ohms indicates a short circuit or shorted sensor.

Very high ohms indicates an open circuit. Check the grounds at the intake manifold fuel rail mounts.

The temperature sensor is known as a NTC, negative temperature coefficient, meaning that as the temperature of the sensor increases the resistance decreases and visa-versa.

Hope this helps. Also check the condition of the engine wiring harness as there have been many posts on harnesses that are plagued with crumbling insulation.

Alan Carlo