Fuel and Engine Management 85
View of the 1.6 liter engine showing the engine management components. Air cleaner removed for clarity.
series of tests on various components in the system
and records the results, If a fault is discovered, the
ECM warning lamp on the instrument cluster will
illuminate while the engine is running. When the self
diagnosis mode is activated, the ECM warning lamp
will flash codes indicating the area in which the fault
has occurred.
This function is very useful in locating system
faults, particularly intermittent problems. However,
the self diagnosis mode does not provide comprehen-
sive testing of the EFI system, and therefore should
always be used in conjunction with the other test
procedures described later in this section in order to
accurately locate system faults.
The high energy electronic ignition system con-
sists of a distributor and an ignition coil.
The distributor has two functions. The first is to
produce and distribute secondary high tension voltage
to the spark plugs.
The second function is to provide the control unit
with information on engine speed and crankshaft
position.
The ignition timing is constantly adjusted by the
control unit to suit varying engine and vehicle oper-
ating conditions.
In the fuel injection system, a metered amount of
fuel is sprayed into the air stream. The air/fuel
mixture then enters the combustion chamber via the
inlet valves.
On 1.6 liter engines, the fuel is injected by a single
injector, located above the throttle valve within the
throttle body assembly. The injector fires twice per
engine revolution under most operating conditions.
On 1.8 liter engines, four injectors are used. The
fuel is distributed to the injectors via the fuel rail. All
injectors fire simultaneous ly once per engine revolu-
tion under most operating conditions.
Under conditions of high load the control unit
may signal the injector(s) to fire more often. However,
if the engine speed exceeds 6 700 rpm the control unit
will cease firing the injectors until the engine speed is
below 6 200 rpm.
Fuel is supplied under pressu re by an electric fuel
pump mounted in the fuel tank and the pressure is
regulated by a pressure regulator.
On 1.6 liter engines, the regulator consists of a
spring tensioned diaphragm which is mounted to the
side of the throttle body assembly. The fuel pressure is
regulated by the tension of the spring against the
diaphragm, opening and closing the fuel return port.
On 1.8 liter engines, the pressure regulator is
mounted adjacent to the fuel rail and consists of a
diaphragm with fuel pressu re acting on one side and
spring tension and manifold vacuum acting on the
Fuel and Engine Management 105
DISTRIBUTOR
To Remove and Install
(1) Disconnect the negative battery terminal.
(2) Disconnect the distribu tor wiring connec-
tors.
(3) Disconnect the high tension leads from the
spark plugs. (4) Remove the distributor cap retaining screws
and remove the cap and high tension leads from the
vehicle. (5) Turn the engine in the normal direction of
rotation until the mark on the crankshaft pulley aligns
with the timing pointer and the rotor is pointing
towards the No. 1 spark pl ug lead terminal on the
distributor cap. (6) Mark the distributor body to camshaft hous-
ing relationship to aid in setting the ignition timing on
installation.
(7) Remove the distributor retaining nuts and
withdraw the distributor from the camshaft housing.
Installation is a reversal of the removal procedure
with attention to the following points:
(1) Ensure that the engine has not been rotated
while the distributor has been removed. If the engine
has been rotated, align the timing marks and ensure
that No. 1 piston is on the compression stroke.
(2) Check and renew the distributor base O ring
if the sealing quality is suspect. (3) Install the distributor to the camshaft
hous-
ing, aligning the coupling with the slot in the camshaft
and ensuring that the rotor does not move in relation
to the distributor body. Align the marks made on
removal. (4) Install and securely tighten the distributor
retaining nuts. (5) Install the distributor cap and tighten
the
retaining screws.
(6) Connect the distributor wiring connector.
(7) Connect the negative battery terminal and
check the ignition timing as previously described in
this section.
To Dismantle and Assemble
With the distributor removed from the engine and
the distributor cap removed, dismantle the distributor
as follows:
(1) Disconnect the pickup coil wiring connector
from the control module. (2) Measure the resistance between the terminals
on the pickup coil wiring connector and the distribu-
tor body. The r esistance should be infinity.
(3) Measure the resistance between the terminals
View of the distributor removed from the engine show-
ing the pickup coil connector. 0 RING RETAINING SPRING
Dismantled view of the distributor.
