Table of Contents
Advertisement
ENGINE
FUEL SYSTEM
COOLANT
TEMP.
SENSOR - ATMOSPHERIC
PRESSURE SENSOR - FAST IDLE SOLENOID
AND IDLE SPEED CONTROLS
COOLANT TEMPERATUR SENSOR
(CTS)
The coolant temperature
sensor (threaded into
the thermostat
housing) provides input to the
electronic
control
unit (ECU), which, in turn,
corrects the air/fuel mixture ratio according to the
engine coolant temperature.
ATMOSPHERIC PRESSURE SENSOR
The atmostpheric Pressure Sensor consists of:
• an atmospheric pressure capsule (1A)
• A potentiometer
(2A)
The atmospheric
pressure
sensor is located
beneath the front passenger seat adjacent to the
electronic control unit (EeU).
The potentiometer B + voltage is provided by the
fuel injection relay.
The potentiometer
wi per
arm position
is
determined by the atmospheric pressure capsule.
The atmospheric
pressure sensor provides
a
voltage input to the electronic control unit (EeU)
that represents the current ambient atmospheric
pressure.
The ECU uses the input to compensate for any
altitude changes.
The voltage provided to the Eeu is:
• low at sea level
• high at 1,230 meters (4,000 feet) -
approximately 90% of the B + voltage.
FAST IDLE SOLENOID
The fast idle solenoid (2B) is attached to the idle
bypass unit body.
Each time the engine is started, the fast idle
solenoid is energized.
It is also energized when the air conditioner
compressor is operating.
Two relays control the fast idle solenoid.
After
engine start-up, the start-up time relay
maintains
the
solenoid
energized
for
approxi mately 3 seconds.
e2-7
When the air conditioner
compressor is turned
ON, the Ale relay energizes the fast idle solenoid.
The timer relay is located near the left headlight
and Ale relay behind right headlight.
IDLE SPEED CONTROLS
The engine idle speed is controlled by the position
of the adj ustment screw (1B) on the ai r bypass
unit located on the firewall.
Engine idle speed (hot): vehicles equipped with
an automatic transmission 700 .±. 50 rpm in drive
(D).
r
)
[
[
Advertisement
Table of Contents
Troubleshooting
