1998 OPEL FRONTERA rack

6E–347 ENGINE DRIVEABILITY AND EMISSIONS
the secondary ignition circuit to flow through the spark
plug to the ground.
TS24047
Ignition Control PCM Output
The PCM provides a zero volt (actually about 100 mV to
200 mV) or a 5-volt output signal to the ignition control (IC)
module. Each spark plug has its own primary and
secondary coil module (”coil-at-plug”) located at the spark
plug itself. When the ignition coil receives the 5-volt signal
from the PCM, it provides a ground path for the B+ supply
to the primary side of the coil-at -plug module. This
energizes the primary coil and creates a magnetic field in
the coil-at-plug module. When the PCM shuts off the
5-volt signal to the ignition control module, the ground
path for the primary coil is broken. The magnetic field
collapses and induces a high voltage secondary impulse
which fires the spark plug and ignites the air/fuel mixture.
The circuit between the PCM and the ignition coil is
monitored for open circuits, shorts to voltage, and shorts
to ground. If the PCM detects one of these events, it will
set one of the following DTCs:
P0351: Ignition coil Fault on Cylinder #1
P0352: Ignition coil Fault on Cylinder #2
P0353: Ignition coil Fault on Cylinder #3
P0354: Ignition coil Fault on Cylinder #4
P0355: Ignition coil Fault on Cylinder #5
P0356: Ignition coil Fault on Cylinder #6
Knock Sensor (KS) PCM Input
The knock sensor (KS) system is comprised of a knock
sensor and the PCM. The PCM monitors the KS signals
to determine when engine detonation occurs. When a
knock sensor detects detonation, the PCM retards the
spark timing to reduce detonation. Timing may also be
retarded because of excessive mechanical engine or
transmission noise.
Powertrain Control Module (PCM)
The PCM is responsible for maintaining proper spark and
fuel injection timing for all driving conditions. To provideoptimum driveability and emissions, the PCM monitors
the input signals from the following components in order
to calculate spark timing:
Engine coolant temperature (ECT) sensor.
Intake air temperature (IAT) sensor.
Mass air flow (MAF) sensor.
PRNDL input from transmission range switch.
Throttle position (TP) sensor.
Vehicle speed sensor (VSS) .
Crankshaft position (CKP) sensor.
Spark Plug
Although worn or dirty spark plugs may give satisfactory
operation at idling speed, they frequency fail at higher
engine speeds. Faulty spark plugs may cause poor fuel
economy, power loss, loss of speed, hard starting and
generally poor engine performance. Follow the
scheduled maintenance service recommendations to
ensure satisfactory spark plug performance. Refer to
Maintenance and Lubrication.
Normal spark plug operation will result in brown to
grayish-tan deposits appearing on the insulator portion of
the spark plug. A small amount of red-brown, yellow, and
white powdery material may also be present on the
insulator tip around the center electrode. These deposits
are normal combustion by-products of fuels and
lubricating oils with additives. Some electrode wear will
also occur. Engines which are not running properly are
often referred to as “misfiring.” This means the ignition
spark is not igniting the air/fuel mixture at the proper time.
While other ignition and fuel system causes must also be
considered, possible causes include ignition system
conditions which allow the spark voltage to reach ground
in some other manner than by jumping across the air gap
at the tip of the spark plug, leaving the air/fuel mixture
unburned. Misfiring may also occur when the tip of the
spark plug becomes overheated and ignites the mixture
before the spark jumps. This is referred to as
“pre-ignition.”
Spark plugs may also misfire due to fouling, excessive
gap, or a cracked or broken insulator. If misfiring occurs
before the recommended replacement interval, locate
and correct the cause.
Carbon fouling of the spark plug is indicated by dry, black
carbon (soot) deposits on the portion of the spark plug in
the cylinder. Excessive idling and slow speeds under
light engine loads can keep the spark plug temperatures
so low that these deposits are not burned off. Very rich
fuel mixtures or poor ignition system output may also be
the cause. Refer to DTC P0172.
Oil fouling of the spark plug is indicated by wet oily
deposits on the portion of the spark plug in the cylinder,
usually with little electrode wear. This may be caused by
oil during break-in of new or newly overhauled engines.
Deposit fouling of the spark plug occurs when the normal
red-brown, yellow or white deposits of combustion by
products become sufficient to cause misfiring. In some
c a s e s , t h e s e d e p o s i t s m a y m e l t a n d f o r m a s h i n y g l a z e o n
the insulator around the center electrode. If the fouling is
found in only one or two cylinders, valve stem clearances
or intake valve seals may be allowing excess lubricating

6E–348
ENGINE DRIVEABILITY AND EMISSIONS
oil to enter the cylinder, particularly if the deposits are
heavier on the side of the spark plug facing the intake
valve.
TS23995
Excessive gap means that the air space between the
center and the side electrodes at the bottom of the spark
plug is too wide for consistent firing. This may be due to
improper gap adjustment or to excessive wear of the
electrode during use. A check of the gap size and
comparison to the gap specified for the vehicle in
Maintenance and Lubrication will tell if the gap is too wide.
A spark plug gap that is too small may cause an unstable
idle condition. Excessive gap wear can be an indication
of continuous operation at high speeds or with engine
loads, causing the spark to run too hot. Another possible
cause is an excessively lean fuel mixture.
TS23992
Low or high spark plug installation torque or improper
seating can result in the spark plug running too hot and
can cause excessive center electrode wear. The plug
and the cylinder head seats must be in good contact for
proper heat transfer and spark plug cooling. Dirty or
damaged threads in the head or on the spark plug cankeep it from seating even though the proper torque is
applied. Once spark plugs are properly seated, tighten
them to the torque shown in the Specifications Table. Low
torque may result in poor contact of the seats due to a
loose spark plug. Overtightening may cause the spark
plug shell to be stretched and will result in poor contact
between the seats. In extreme cases, exhaust blow-by
and damage beyond simple gap wear may occur.
Cracked or broken insulators may be the result of
improper installation, damage during spark plug
re-gapping, or heat shock to the insulator material. Upper
insulators can be broken when a poorly fitting tool is used
during installation or removal, when the spark plug is hit
from the outside, or is dropped on a hard surface. Cracks
in the upper insulator may be inside the shell and not
visible. Also, the breakage may not cause problems until
oil or moisture penetrates the crack later.
TS23994
A broken or cracked lower insulator tip (around the center
electrode) may result from damage during re-gapping or
from “heat shock” (spark plug suddenly operating too
hot).
TS23993

6E–349 ENGINE DRIVEABILITY AND EMISSIONS
Damage during re-gapping can happen if the gapping
tool is pushed against the center electrode or the
insulator around it, causing the insulator to crack.
When re-gapping a spark plug, make the adjustment
by bending only the ground side terminal, keeping the
tool clear of other parts.
”Heat shock” breakage in the lower insulator tip
generally occurs during several engine operating
conditions (high speeds or heavy loading) and may be
caused by over-advanced timing or low grade fuels.
Heat shock refers to a rapid increase in the tip
temperature that causes the insulator material to
crack.
Spark plugs with less than the recommended amount of
service can sometimes be cleaned and re-gapped , then
returned to service. However, if there is any doubt about
the serviceability of a spark plug, replace it. Spark plugs
with cracked or broken insulators should always be
replaced.
A/C Clutch Diagnosis
A/C Clutch Circuit Operation
A 12-volt signal is supplied to the A/C request input of the
PCM when the A/C is selected through the A/C control
switch.
The A/C compressor clutch relay is controlled through the
PCM. This allows the PCM to modify the idle air control
position prior to the A/C clutch engagement for better idle
quality. If the engine operating conditions are within their
specified calibrated acceptable ranges, the PCM will
enable the A/C compressor relay. This is done by
providing a ground path for the A/C relay coil within the
PCM. When the A/C compressor relay is enabled,
battery voltage is supplied to the compressor clutch coil.
The PCM will enable the A/C compressor clutch
whenever the engine is running and the A/C has been
requested. The PCM will not enable the A/C compressor
clutch if any of the following conditions are met:
The throttle is greater than 90%.
The engine speed is greater than 6315 RPM.
The ECT is greater than 119C (246F).
The IAT is less than 5C (41F).
The throttle is more than 80% open.
A/C Clutch Circuit Purpose
The A/C compressor operation is controlled by the
powertrain control module (PCM) for the following
reasons:
It improvises idle quality during compressor clutch
engagement.
It improvises wide open throttle (WOT) performance.
It provides A/C compressor protection from operation
with incorrect refrigerant pressures.
The A/C electrical system consists of the following
components:
The A/C control head.
The A/C refrigerant pressure switches.
The A/C compressor clutch.
The A/C compressor clutch relay.
The PCM.
A/C Request Signal
This signal tells the PCM when the A/C mode is selected
at the A/C control head. The PCM uses this to adjust the
idle speed before turning on the A/C clutch. The A/C
compressor will be inoperative if this signal is not
available to the PCM.
Refer to
A/C Clutch Circuit Diagnosis for A/C wiring
diagrams and diagnosis for A/C electrical system.
General Description (Exhaust Gas
Recirculation (EGR) System)
EGR Purpose
The exhaust gas recirculation (EGR) system is use to
reduce emission levels of oxides of nitrogen (NOx). NOx
emission levels are caused by a high combustion
temperature. The EGR system lowers the NOx emission
levels by decreasing the combustion temperature.
057RW002
Linear EGR Valve
The main element of the system is the linear EGR valve.
The EGR valve feeds small amounts of exhaust gas back
into the combustion chamber. The fuel/air mixture will be
diluted and combustion temperatures reduced.
Linear EGR Control
The PCM monitors the EGR actual positron and adjusts
the pintle position accordingly. The uses information from
the following sensors to control the pintle position:
Engine coolant temperature (ECT) sensor.
Throttle position (TP) sensor.
Mass air flow (MAF) sensor.
Linear EGR Valve Operation and Results
of Incorrect Operation
The linear EGR valve is designed to accurately supply
EGR to the engine independent of intake manifold
vacuum. The valve controls EGR flow from the exhaust

6E–354
ENGINE DRIVEABILITY AND EMISSIONS
ILLUSTRATIONTOOL NO.
TOOL NAME
5-8840-2607-0
(J 41413)
EVAP Pressure/Purge
Diagnostic Station
5-8840-2608-0
(J 41416)
Ultrasonic Leak Detector
1. 5-8840-2607-0 (J-41413)EVAP Pressure/Purge
Diagnostic Station is a multipurpose tool which is
used to perform several diagnostic procedures for
enhanced emission testing. The station will
accommodate a nitrogen gas filled cylinder which is
used to pressurize the vehicle EVAP system for a
leakdown test and leak location test when a vehicle is
repaired for leakage in the enhanced evaporative
emission control system. It also has two additional
gauges (inches of mercury and inches of water) which
are used to measure both source vacuum and EVAP
canister purge vacuum to verify correct operation and
vapor flow within the canister purge circuit.
2. 5-8840-2608-0 (J-41416) Ultrasonic Leak Detector is
a microprocessor-based device used to detect leaks
in the enhanced evaporative emission control
system. The evaporative system is pressurized to 30
inches of water using the 5-8840-2607-0 (J-41413)
EVAP Pressure/Purge Diagnostic System. Small
leaks in the EVAP system will emit sound at a high
frequency undetectable by a human ear but
detectable with the 5-8840-2608-0 (J-41416). The
technician traces along the evaporative system and
can pinpoint leaks due to corroded lines, cracked
hoses, or a damaged EVAP component. The
detector includes a high quality set of headphones to
block out surrounding shop noise and the LED
sensitivity meter allows a visual reference for locating
leaks in conjunction with the audio output heard
through the headphones. Powered by (1) nine volt
battery.

6G–5 ENGINE LUBRICATION
051RS005
Oil Strainer
Check the oil strainer for cracking and scoring. If cracking
and scoring are found, the oil strainer must be replaced.
051RS006
Reassembly
1. Install drive gear (11).
2. Install driven gear (10).
3. Install oil pump cover (9) and first, loosely tighten all of
the attaching screws. Next, tighten the attaching
screws to the specified torque.
Torque : 10 Nꞏm (1.0 Kgꞏm/89 lb in)
After installation, check that the gear rotates
smoothly.
4. Install relief valve (8) and apply engine oil to the relief
valve and spring (7).
5. Install spring (7).6. Install the plug (6).
Torque : 8 Nꞏm (0.8 Kgꞏm/69 lb in)
051RS007
7. Install oil pump assembly (5).
Carefully remove any oil from the cylinder body and
the pump. Apply sealant (TB–1207B or equivalent)
to the pump fitting face as shown in illustration. Take
care that sealant is not applied to oil port surfaces.
The oil pump assembly must be installed within 5
minutes after sealant application before the sealant
hardens.
CAUTION: Do not apply an excessive amount of
sealant to the contact surface. Applying too much
sealant will overflow the contact surfaces. This
could cause serious damage to the engine.
Attach oil pump assembly to cylinder body.
Tighten the oil pump fixing bolts.
Torque : 25 Nꞏm (2.5 Kgꞏm/18 lbꞏft)
051RW002

6H–2
ENGINE SPEED CONTROL SYSTEM
Accelerator Pedal Control Cable
Removal
1. Loosen the adjusting nut(5) on the cable bracket
mounted on the common chamber.
2. Remove cable clip(3).
3. Disconnect accelerator pedal (AP) control cable(6).
(on throttle valve side)
4. Disconnect AP control cable(1). (on AP pedal(7) side)
5. Remove molding cap(2).
6. Remove AP control cable(4).
101RW001
Inspection
Check the following items, and replace the control cable if
any abnormality is found:
The control cable should move smoothly.
The control cable should not be bent or kinked.
The control cable should be free of damage and
corrosion.
Installation
1. Install AP control cable(4).
2. Install molding cap(2).
3. Connect AP control cable(1). (on AP side)
4. Connect AP control cable(6). (on throttle valve side)
5. Install cable clip(3).
6. Install adjusting nut(5).
101RW001
Adjustment
1. Loosen adjusting nut and lock nut.
2. Pull outer cable while closing fully the throttle valve.
3. Tighten adjusting nut and lock nut temporarily.
4. Loosen adjusting nut by three turns and tighten lock
nut.
Then, manually operating the throttle valve, make
sure that the valve lever returns up to the stopper
screw.
If it does not reach the stopper screw, repeat from
step 1.
035RW004
Legend
(1) Clearance
(2) Lock Nut
(3) Adjusting Nut

6H–3 ENGINE SPEED CONTROL SYSTEM
Accelerator Pedal
Accelerator Pedal and Associated
Parts
035RW028
Legend
(1) Accelerator Pedal Control Cable
(2) Accelerator Pedal Assembly
Removal
1. Accelerator Pedal control cable(1).
2. Accelerator Pedal assembly(2).
Installation
1. Accelerator pedal assembly(2).
2. Accelerator pedal control cable(1).
Adjustment
Manual Transmission:
Rotate counterclockwise to loosen the lock nut and
screw the stopper bolt in sufficiently.
Fully depress the pedal and hold it there with your
hand. Next, rotate the stopper bolt until it hits the
stopper of pedal bracket. Then, lock the stopper bolt
there.
Automatic Transmission:
Rotate counterclockwise to loosen the kickdown
switch sufficiently.
Fully depress the pedal and hold it there with your
hand. Rotate the switch clockwise and then rotate
further by 1/2 turn from the position where the switch
clicks. Lock the switch there.
Step on the accelerator pedal and make sure that you
can hear a clicking sound at the full stroke position.

6A – 12 ENGINE MECHANICAL
Drive Belt Adjustment
Check the drive belt tension
Depress the drive belt mid-portion with a 98 N (10 kg/
22 lb) force.
Drive Belt Deflection: 10 mm (0.39 in)
Check the drive belt for cracking and other damage.
Legend
(1) Crankshaft pulley
(2) Generator pulley
(3) Cooling fan pulley
(4) A/C compressor pulley
(5) Belt tensioner pulley
Cooling Fan Pulley Drive Belt
Fan belt tension is adjusted by moving the generator.
Depress the drive belt mid-portion with a 98 N (10 kg/
22 lb) force.Legend
(1) Crankshaft pulley
(2) Generator pulley
(3) Cooling fan pulley
Compressor Pulley Drive Belt
Move the tensioner pulley as required to adjust the
compressor drive belt tension.
Depress the drive belt mid-portion with a 98 N (10 kg/
22 lb) force.
Legend
(1) Crankshaft pulley
(2) Generator pulley
(3) Cooling fan pulley
(4) A/C compressor pulley
(5) Belt tensioner pulley
5
3
24
1
012RW110
3
2
1
012RW084
5
3
24
1
012RW110