Fuel Temperature Sensor; Fuel Pressure Sensor - Fiat 1998 Marea Service Manual

Engine
Fuel system
14
Marea- Marea Weekend 9^9
ENGINE COOLANT TEMPERATURE SEN-
SOR
This sensor is fitted on the thermostat and
measures the temperature of the engine cool-
ant by means of an NTC thermistor with a
negative resistance coefficient.
The sensor is produced using semiconductor
technology, therefore if the temperature of the
sensor element increases as the temperature of
the coolant increases, the value of the resis-
tance decreases.
As the resistance variation is not linear, a tem-
perature increase is higher at lower tempera-
tures than at higher ones.
1. NTC resistance
2. Sensor body
3. Electrical connector

FUEL TEMPERATURE SENSOR

This sensor is fitted on the return manifold and
measures the temperature of the fuel by means
of an NTC thermistor with a negative resis-
tance coefficient.
For the operation of the sensor, refer to the
previous description of the coolant temperature
sensor.

FUEL PRESSURE SENSOR

This sensor is fitted at the centre of the fuel
supply manifold (rail) and has the task of pro-
viding the injection control unit with a feed-
back signal for:
- regulating the injection pressure;
- regulating the duration of the injection.
™
99 range
Print n° 506.763/14