fuel pressure OPEL FRONTERA 1998 Manual Online

6E–283 ENGINE DRIVEABILITY AND EMISSIONS
Cuts Out, Misses Symptom
StepNo Ye s Va l u e ( s ) Action
101. Visually/physically inspect for the following
conditions:
Restricted air intake system. Check for a
possible collapsed air intake duct, restricted
air filter element, or foreign objects blocking
the air intake system.
Throttle body. Check for objects blocking the
IAC passage or throttle bore, excessive
deposits in the IAC passage and on the IAC
pintle, and excessive deposits in the throttle
bore and on the throttle plate.
Large vacuum leak. Check for a condition that
causes a large vacuum leak, such as an
incorrectly installed or faulty PCV valve or
brake booster hose disconnected .
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 8
11Check the injector connections. If any of the injectors
are connected to an incorrect cylinder, correct as
necessary.
Was a problem found?
—Verify repairGo to Step 12
121. Perform the “Injector Coil/Balance Test” in Fuel
Metering System
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 13
131. Check for fuel in the pressure regulator vacuum
hose.
2. If fuel is present, replace the fuel pressure regulator
assembly. Refer to
Fuel Metering System.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 14
141. Check for proper ignition voltage output with spark
tester J 26792 (ST-125). Refer to
Electronic Ignition
System
for the procedure.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 15
151. Remove spark plugs. Check for wet plugs, cracks,
wear, improper gap, burned electrodes, or heavy
deposits. Refer to
Electronic Ignition System.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 16
161. Check for a loose ignition coil ground.
Refer to
Electronic Ignition System.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 17

6E–285 ENGINE DRIVEABILITY AND EMISSIONS
Hesitation, Sag, Stumble Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Momentary lack of response as the accelerator is
pushed down. Can occur at any vehicle speed. Usually
most pronounced when first trying to make the vehicle
move, as from a stop sign. May cause the engine to stall
if severe enough.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
41. Check the fuel control heated oxygen sensors
(HO2S, B1S1 and B2S1). The fuel control heated
oxygen sensors (HO2S) should respond quickly to
different throttle positions. If they don’t, check them
for silicon or other contaminants from fuel or use of
improper RTV sealant. The sensors may have a
white powdery coating.
Silicon contamination causes a high but false
HO2S signal voltage (rich exhaust indication).
The PCM will then reduce the amount of fuel
delivered to the engine, causing a severe
driveability problem. For more information, refer
to
Powertrain Control Module (PCM) and Sensors.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 5
51. Check the fuel pressure. Refer to Fuel System
Pressure Test.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 6
6Observe the TP angle display on Tech 2 while slowly
increasing throttle pedal.
Does the TP angle display steadily increase from 0% at
closed throttle to 100% at WOT?
—Go to Step 7Go to Step 18
7Monitor the long term fuel trim on Tech 2.
Is the long term fuel trim significantly in the negative
range (rich condition)?
—Go to Step 8Go to Step 9
81. Check items that can cause the engine to run rich.
Refer to
Diagnostic Aids in DTC P0172 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 10
91. Check items that can cause the engine to run lean.
Refer to
Diagnostic Aids in DTC P0171 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 10

6E–310
ENGINE DRIVEABILITY AND EMISSIONS
Pedal Stroke Adjustment Procedure
1. Loosen the jam nut and rotate the kick-down switch
counterclockwise.
TS24039
2. Fully depress the pedal and hold it by hand. Rotate
the switch clockwise until the switch clicks.
3. Rotate the switch 1/2 turn further and lock it in this
position by tightening the jam nut.
TS24040
4. Step on the accelerator pedal and make sure there is
a clicking sound at the full-stroke position.
Fuel Filter Cap
General Description
The fuel filler cap includes a vacuum valve and a pressure
valve.If high vacuum or high pressure occurs in the fuel tank,
each valve works to adjust the pressure in order to
prevent damage to the tank at the EGR valve.
TS23767
Inspection Procedure
NOTE: Replace the fuel filler cap with the same type of
filler cap that was originally installed on the vehicle.
Check the seal ring in the filler cap for any abnormality
and for seal condition.
Replace the filler cap if any abnormality is found.
Fuel Filter
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the fuel filler cap.
041RW005

6E–315 ENGINE DRIVEABILITY AND EMISSIONS
Installation Procedure
1. Install the O-ring backup on the fuel injector.
2. Install the new O-ring on the fuel injector.
3. Install the fuel injector on the fuel rail.
055RW009
4. Use new fuel injector retainer clips to retain the fuel
injector to the fuel rail.
5. Coat the end of the fuel injector with engine oil.
6. Install the fuel rail. Refer to
Fuel Rail.
014RW164
7. Install the upper intake manifold. Refer to Common
Chamber in Engine Mechanical.
8. Install the engine cover.
9. Connect the negative battery cable.
Fuel Pressure Regulator
Removal Procedure
CAUTION: To reduce the risk of fire and personal
injury, it is necessary to relieve the fuel system
pressure before servicing the fuel system
components.
CAUTION: After relieving the system pressure, a
small amount of fuel may be released when servicing
fuel lines or connections. Reduce the chance of
personal injury by covering the fuel line fittings with
a shop towel before disconnecting the fittings. The
towels will absorb any fuel that may leak out. When
the disconnect is completed, place the towel in an
approved container.
NOTE: Compressed air must never be used to test or
clean a fuel pressure regulator, as damage to the fuel
pressure regulator may result.
NOTE: To prevent damage to the fuel pressure regulator,
do not immerse the pressure regulator in solvent.
1. Depressurize the fuel system. Refer to
Fuel Pressure
Relief Procedure
.
2. Disconnect the negative battery cable.
3. Remove the fuel pump relay. Refer to
Fuel Pump
Relay
.
4. Remove the pressure regulator hose from the fuel
pressure regulator.
014RW110

6E–316
ENGINE DRIVEABILITY AND EMISSIONS
5. Remove the two bolts from the protector that secures
the common chamber.
014RW109
6. Remove the fuel pressure regulator attaching screw.
F06RW043
7. Remove the fuel pressure regulator from the fuel rail.
Disassembly Procedure
1. Remove the O-ring from the fuel pressure regulator.
2. Loosen the swivel nut.
3. Remove the fuel return line from the fuel pressure
regulator.
4. Remove the O-ring from the fuel return line.
The O-ring may be left inside the fuel pressure
regulator instead of on the fuel return line.
F06RW043
Assembly Procedure
1. Install a new O-ring on the fuel return line.
2. Install the fuel return line on the fuel pressure
regulator.
NOTE: Do not over-tighten the swivel nut on the fuel
pressure regulator. The fuel pressure regulator can be
damaged and fuel may leak if the swivel nut is
over-tightened.
3. Tighten the swivel nut.
4. Install a new O-ring on the fuel pressure regulator.

6E–317 ENGINE DRIVEABILITY AND EMISSIONS
Installation Procedure
1. Install the fuel pressure regulator attaching screw.
Tighten
Tighten the fuel pressure regulator attaching screw
to 3 Nꞏm (26 lb in.).
F06RW043
2. Install the fuel pressure regulator on the fuel rail.
3. Install the two bolts to the protector that secures the
common chamber.
014RW109
4. Install the pressure regulator hose to the fuel
pressure regulator.
014RW110
5. Install the fuel pump relay. Refer to Fuel Pump Relay.
6. Connect the negative battery cable.
7. Crank the engine until it starts. Cranking the engine
may take longer than usual due to trapped air in the
fuel lines.
Fuel Metering System
Fuel Pressure Relief Procedure
CAUTION: To reduce the risk of fire and personal
injury, it is necessary to relieve the fuel system
pressure before servicing the fuel system
components.
CAUTION: After relieving the system pressure, a
small amount of fuel may be released when servicing
fuel lines or connections. Reduce the chance of
personal injury by covering the fuel line fittings with
a shop towel before you disconnect the fittings. The
towels will absorb any fuel that may leak out. When
the disconnect is completed, place the towel in an
approved container.
1. Remove the fuel cap.

6E–320
ENGINE DRIVEABILITY AND EMISSIONS
IMPORTANT:An eight-digit identification number is
stamped on the side of the fuel rail. Refer to this number
when you service the fuel rail or when a replacement part
is required.
TS24022
Before removal, the fuel rail assembly may be cleaned
with a spray type engine cleaner. Follow the spray
package instructions. Do not immerse the fuel rails in
liquid cleaning solvent.
1. Depressurize the fuel system. Refer to Fuel Pressure
Relief Procedure in this Section.
2. Disconnect the negative battery cable.
3. Remove the engine cover.
4. Disconnect the accelerator pedal cable from throttle
body and cable bracket.
5. Disconnect the connectors from manifold absolute
pressure sensor, solenoid valve, electric vacuum
sensing valve.
6. Disconnect the vacuum hose on canister VSV and
positive crankcase ventilation hose.
7. Remove the common chamber. Refer to the common
chamber in Engine Mechanical.
1. Lift up carefully on the fuel injectors. Do not
separate the fuel injectors from the fuel rail.
2. If an injector becomes separated from the fuel
rail, the infector O-ring seals and the retainer clip
must be replaced.
3. Drain residual fuel into an approved container.
014RW164
8. If removal of the fuel pressure regulator is necessary,
refer to
Fuel Pressure Regulator.
9. If removal of the fuel injectors is necessary, refer to
Fuel Injectors.
Installation Procedure
1. If the fuel injectors were removed, install them. Refer
to
Fuel Injectors.
2. If the fuel pressure regulator was removed, install it.
Refer to
Fuel Pressure Regulator.
3. Install the common chamber. Refer to common
chamber in engine Mechanical.
014RW164

6E–321 ENGINE DRIVEABILITY AND EMISSIONS
4. Connect the vacuum hose on Canister VSV and
positive crankcase ventilation hose.
5. Connect the connectors to manifold absolute
pressure sensor, solenoid valve, electric vacuum
sensing valve.
6. Connect the accelerator pedal cable to throttle body
and cable bracket.
7. Install the engine cover.
8. Connect the negative battery cable.
9. Crank the engine until it starts. Cranking the engine
may take longer than usual due to trapped air in the
fuel rail and in the injectors.
Fuel Tank
Removal Procedure
1. Disconnect the negative battery cable.
2. Loosen the fuel filler cap.
3. Drain the fuel from the tank into an approved
container.
4. Install and tighten the drain plug.
Tighten
Tighten the drain plug to 20 Nꞏm (14 lb ft.).
5. Disconnect the fuel filler hose at the fuel tank.
6. Disconnect the air breather hose at the fuel tank.
TS23796
7. Remove the undercover retaining bolts.
8. Remove the undercover.
TS23797
9. Disconnect the wiring connector to the fuel pump.
10. Disconnect the wiring connector to the fuel gauge
unit.
11. Remove the fuel gauge unit connector from the
bracket.
12. Disconnect the EVAP vapor hose.
13. Disconnect the fuel supply hose.
14. Disconnect the fuel return hose.
Plug the hoses to prevent dust from entering the
hoses.
TS23769

6E–337 ENGINE DRIVEABILITY AND EMISSIONS
0018
Knock Sensor
Insufficient gasoline octane levels may cause detonation
in some engines. Detonation is an uncontrolled explosion
(burn) in the combustion chamber. This uncontrolled
explosion results from a flame front opposite that of the
normal flame front produced by the spark plug. The
rattling sound normally associated with detonation is the
result of two or more opposing pressures (flame fronts)
colliding within the combustion chamber. Light
detonation is sometimes considered normal, but heavy
detonation could result in engine damage.
A knock sensor system is used to control detonation. This
system is designed to retard spark timing up to 20
degrees to reduce detonation in the engine. This allows
the engine to use maximum spark advance to improve
driveability and fuel economy.
The knock sensor system has two major components:
The knock sensor (KS) module.
The knock sensor.
The knock sensor, mounted in the engine block near the
cylinders, detects abnormal vibration in the engine. The
sensor produces an AC output signal of about 10
millivolts. The signal amplitude and frequency are
dependent on the amount of knock being experienced.
The signal voltage increases with the severity of the
knock. This signal voltage is input to the PCM. The PCM
then retards the ignition control (IC) spark timing based
on the KS signal being received.
The PCM determines whether knock is occurring by
comparing the signal level on the KS circuit with the
voltage level on the noise channel. The noise channel
allows the PCM to reject any false knock signal by
indicating the amount of normal engine mechanical noise
present. Normal engine noise varies depending on the
engine speed and load. If the voltage level on the KS
noise channel circuit is below the range considered
normal, DTC P0327 will set, indicating a fault in the KScircuit or the knock sensor. If the PCM determines that an
abnormal minimum or maximum noise level is being
experienced, DTC P0325 will set.
The PCM contains a knock sensor (KS) module. The KS
module contains the circuitry which allows the PCM to
utilize the KS signal and diagnose the KS sensor and the
KS circuitry. If the KS module is missing or faulty, a
continuous knock condition will be indicated, and the
PCM will set DTC P0325.
Although it is a plug-in device, the KS module is not
replaceable. If the KS module is faulty, the entire PCM
must be replaced.
0009
Linear Exhaust Gas Recirculation (EGR)
Control
The PCM monitors the exhaust gas recirculation (EGR)
actual position and adjusts the pintle position accordingly.
The PCM 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.
Mass Air Flow (MAF) Sensor
The mass air flow (MAF) sensor measures the difference
between the volume and the quantity of air that enters the
engine. “Volume” means the size of the space to be filled.
“Quantity” means the number of air molecules that will fit
into the space. This information is important to the PCM
because heavier, denser air will hold more fuel than
lighter, thinner air. The PCM adjusts the air/fuel ratio as
needed depending on the MAF value. Tech 2 reads the
MAF value and displays it in terms of grams per second
(gm/s). At idle, Tech 2 should read between 4-7 gm/s on a
fully warmed up engine. Values should change quickly on
acceleration. Values should remain stable at any given

6E–338
ENGINE DRIVEABILITY AND EMISSIONS
RPM. A failure in the MAF sensor or circuit will set DTC
P0101, DTC P0102, or DTC P0103.
0007
Manifold Absolute Pressure (MAP) Sensor
The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure (vacuum). The
MAP sensor signal voltage to the PCM varies from below
2 volts at idle (high vacuum) to above 4 volts with the
ignition ON, engine not running or at wide-open throttle
(low vacuum).
The MAP sensor is used to determine the following:
Manifold pressure changes while the linear EGR flow
test diagnostic is being run. Refer to
DTC P0401.
Engine vacuum level for other diagnostics.
Barometric pressure (BARO).
If the PCM detects a voltage that is lower than the
possible range of the MAP sensor, DTC P0107 will be set.
A signal voltage higher than the possible range of the
sensor will set DTC P0108. An intermittent low or high
voltage will set DTC P1107 or DTC P1106, respectively.
The PCM can detect a shifted MAP sensor. The PCM
compares the MAP sensor signal to a calculated MAP
based on throttle position and various engine load factors.
If the PCM detects a MAP signal that varies excessively
above or below the calculated value, DTC P0106 will set.
055RW004
Powertrain Control Module (PCM)
The powertrain control module (PCM) is located in the
passenger compartment below the center console. The
PCM controls the following:
Fuel metering system.
Transmission shifting (automatic transmission only).
Ignition timing.
On-board diagnostics for powertrain functions.
The PCM constantly observes the information from
various sensors. The PCM controls the systems that
affect vehicle performance. The PCM performs the
diagnostic function of the system. It can recognize
operational problems, alert the driver through the MIL
(Service Engine Soon lamp), and store diagnostic trouble
codes (DTCs). DTCs identify the problem areas to aid the
technician in making repairs.
This engine uses 2 different control modules:
IPCM-6KT for automatic transmission-equipped
vehicles.
ISFI-6 for manual transmission-equipped vehicles.
PCM Function
The PCM supplies either 5 or 12 volts to power various
sensors or switches. The power is supplied through
resistances in the PCM which are so high in value that a
test light will not light when connected to the circuit. In
some cases, even an ordinary shop voltmeter will not give
an accurate reading because its resistance is too low.
Therefore, a digital voltmeter with at least 10 megohms
input impedance is required to ensure accurate voltage
readings. Tool J 39200 meets this requirement. The PCM
controls output circuits such as the injectors, IAC, cooling
fan relays, etc., by controlling the ground or the power
feed circuit through transistors of following device.
Output Driver Module (ODM)