pressure relief OPEL FRONTERA 1998 Owner's Manual

6E–91 ENGINE DRIVEABILITY AND EMISSIONS
Fuel System Diagnosis
StepNo Ye s Va l u e ( s ) Action
10Locate and repair the loss of vacuum to the fuel
pressure regulator.
Is the action complete?
—Verify repair—
11Replace the fuel pressure regulator.
Is the action complete?
—Verify repair—
121. Run the fuel pump with Tech 2.
2. After pressure has built up, turn off the pump and
clamp the supply hose shut with suitable locking
pliers.
Does the fuel pressure indicated by the fuel pressure
gauge remain constant?
—Go to Step 13Go to Step 15
13Visually inspect the fuel supply line and repair any
leaks.
Was a problem found?
—Verify repairGo to Step 14
14Remove the fuel tank and inspect for leaky hose or
in-tank fuel line.
Was a problem found?
—Verify repairGo to Step 8
151. If the pliers are still clamped to the fuel supply hose,
remove the locking pliers.
2. With suitable locking pliers, clamp the fuel return
line to prevent fuel from returning to the fuel tank.
3. Run the fuel pump with Tech 2.
4. After pressure has built up, remove power to the
pump.
Does the fuel pressure indicated by the fuel pressure
gauge remain constant?
—Go to Step 11Go to Step 16
16Locate and replace any leaking fuel injector(s).
Is the action complete?
—Verify repair—
17Is the fuel pressure indicated by the fuel pressure
gauge above the specified limit?376 kPa
(55 psi)
Go to Step 18Go to Step 21
181. Relieve the fuel pressure. Refer to the Fuel
Pressure Relief.
2. Disconnect the fuel return line from the fuel rail.
3. Attach a length of flexible hose to the fuel rail return
outlet passage.
4. Place the open end of the flexible hose into an
approved gasoline container.
5. Run the fuel pump with Tech 2.
6. Observe the fuel pressure indicated by the fuel
pressure gauge with the fuel pump running.
Is the fuel pressure within the specified limits?
290-376 kPa
(42-55 psi)
Go to Step 19Go to Step 20
19Locate and correct the restriction in the fuel return line.
Is the action complete?
—Verify repair—
20Visually and physically inspect the fuel rail outlet
passages for a restriction.
Was a restriction found?
—Verify repairGo to Step 11
21Is the fuel pressure indicated by the fuel pressure
gauge above the specified value?
0kPa (0psi)Go to Step 22Go to Step 23

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.
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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.
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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.
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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.).
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2. Install the fuel pressure regulator on the fuel rail.
3. Install the two bolts to the protector that secures the
common chamber.
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4. Install the pressure regulator hose to the fuel
pressure regulator.
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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.
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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.
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6E–343 ENGINE DRIVEABILITY AND EMISSIONS
constant measuring and adjusting of the air/fuel ratio, the
fuel injection system is called a “closed loop” system.
The PCM monitors signals from several sensors in order
to determine the fuel needs of the engine. Fuel is
delivered under one of several conditions called “modes.”
All modes are controlled by the PCM.
Fuel Pressure Regulator
The fuel pressure regulator is a diaphragm-operated
relief valve mounted on the fuel rail with fuel pump
pressure on one side and manifold pressure on the other
side. The fuel pressure regulator maintains the fuel
pressure available to the injector at three times
barometric pressure adjusted for engine load. It may be
serviced separate.
If the pressure is too low, poor performance and a DTC
P0131, DTC P0151,DTC P0171 or DTC P1171 will be the
result. If the pressure is too high, excessive odor and/or a
DTC P0132, DTC P0152,DTC P0172 or DTC P0175 will
be the result. Refer to
Fuel System Diagnosis for
information on diagnosing fuel pressure conditions.
0011
Fuel Pump Electrical Circuit
When the key is first turned “ON,” the PCM energizes the
fuel pump relay for two seconds to build up the fuel
pressure quickly. If the engine is not started within two
seconds, the PCM shuts the fuel pump off and waits until
the engine is cranked. When the engine is cranked and
the 58 X crankshaft position signal has been detected by
the PCM, the PCM supplies 12 volts to the fuel pump relay
to energize the electric in-tank fuel pump.
An inoperative fuel pump will cause a “no-start” condition.
A fuel pump which does not provide enough pressure will
result in poor performance.
Fuel Rail
The fuel rail is mounted to the top of the engine and
distributes fuel to the individual injectors. Fuel is
delivered to the fuel inlet tube of the fuel rail by the fuel
lines. The fuel goes through the fuel rail to the fuel
pressure regulator. The fuel pressure regulator maintainsa constant fuel pressure at the injectors. Remaining fuel
is then returned to the fuel tank.
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Idle Air Control (IAC) Valve
The purpose of the idle air control (IAC) valve is to control
engine idle speed, while preventing stalls due to changes
in engine load. The IAC valve, mounted in the throttle
body, controls bypass air around the throttle plate. By
moving the conical valve (pintle) in (to decrease air flow)
or out (to increase air flow), a controlled amount of air can
move around the throttle plate. If the RPM is too low, the
PCM will retract the IAC pintle, resulting in more air
moving past the throttle plate to increase the RPM. If the
RPM is too high, the PCM will extend the IAC pintle,
allowing less air to move past the throttle plate,
decreasing the RPM.
The IAC pintle valve moves in small steps called counts.
During idle, the proper position of the IAC pintle is
calculated by the PCM based on battery voltage, coolant
temperature, engine load, and engine RPM. If the RPM
drops below a specified value, and the throttle plate is
closed, the PCM senses a near-stall condition. The PCM
will then calculate a new IAC pintle valve position to
prevent stalls.
If the IAC valve is disconnected and reconnected with the
engine running, the idle RPM will be wrong. In this case,
the IAC must be reset. The IAC resets when the key is
cycled “ON” then “OFF.” When servicing the IAC, it
should only be disconnected or connected with the
ignition “OFF.”
The position of the IAC pintle valve affects engine start-up
and the idle characteristics of the vehicle. If the IAC pintle
is fully open, too much air will be allowed into the manifold.
This results in high idle speed, along with possible hard
starting and a lean air/fuel ratio. DTC P0507 or DTC
P1509 may set. If the IAC pintle is stuck closed, too little
air will be allowed in the manifold. This results in a low idle
speed, along with possible hard starting and a rich air/fuel
ratio. DTC P0506 or DTC P1508 may set. If the IAC
pintle is stuck part-way open, the idle may be high or low
and will not respond to changes in the engine load.

6G–2
ENGINE LUBRICATION
General Description
C06RW002
Legend
(1) Oil Strainer
(2) Oil Pump
(3) Relief Valve
(4) Oil Pressure Switch
(5) Oil Filter
(6) Safety Valve
(7) Oil Pressure Unit
(8) Oil Gallery
(9) Crankshaft Bearing(10) Crankshaft
(11) Connecting Rod Bearing
(12) Connecting Rod
(13) Piston
(14) Oil Gallery; Cylinder Head
(15) Camshaft
(16) Camshaft Journal
(17) Front Journal; Camshaft Drive Gear
(18) Rear Journal; Camshaft Drive Gear
(19) Oil Pan

ENGINE FUEL 6C – 5
HIGH PRESSURE OIL PUMP, OIL FLOW
P
33
32
31
30
1
2
3
4
56
8
97
10
11
12
13
14 23 29
25
28
27262415
16
17 18
19 20 21 22
Legend
(1) Camshaft
(2) Balance Shaft
(3) Crankshaft
(4) Oil Cooler and Oil Filter Assembly
(5) Oil Filter Relief Valve 98 Kpa (1 kg/cm
2/14.2 Psi)
(6) Oil Cooler Relief Valve 245 Kpa (2.5 kg/cm2/
36 Psi)
(7) First Oil Pump
(8) Main Oil Relief Valve 588 Kpa (6 kg/cm
2/ 85 Psi)
(9) To Oil Pan
(10) To Oil Pan
(11) Injector
(12) Oil Rail
(13) Sub Oil Filter Relief Valve 98 Kpa (1 kg/cm
2/
14.2 Psi)
(14) Sub Oil Filter
(15) Relief Valve 588 Kpa (6 kg/cm
2/ 85 Psi)
(16) Second Oil Pump(17) Oil Pan
(18) To Oil Pan
(19) Balance Shaft
(20) Cooling Jet Relief Valve 245 Kpa (2.5 kg/cm
2/
36 Psi)
(21) Cooling Jet
(22) To Oil Pan
(23) Two Way Check Valve
(24) Nipple Filter
(25) Edge Filter
(26) Edge Filter
(27) High Pressure Oil Pump Assembly
(28) To Oil Pan
(29) Pressure Control Valve
(30) To Oil Pan
(31) Turbocharger
(32) Oil Gallery
(33) Timing Gear Train
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ENGINE LUBRICATION 6G – 3
To meet a newly adopted electronically controlled fuel
injection system using engine oil two oil pumps have
been provided to increase circulating oil capacity.
The first oil pump serves mainly to lubricate the engine
parts, while the second mainly serves the fuel injectors
and partially cools the pistons.
The oil cooler is provided on the first oil pump side and
uses engine coolant.
OIL FLOW
Legend
(1) Oil Pump
(2) Regulator Valve
(3) Oil Cooler
(4) Oil Filter Relief Valve
(5) Full Flow Filter
(6) Oil Cooler Relief Valve
(7) Gallery
OIL PUMP SPECIFICATIONS
OIL FILTER SPECIFICATIONS
Legend
(1) Oil cooler assembly
(2) Oil filter assembly (25) Edge Filter
(26) Edge Filter
(27) High Pressure Oil Pump Assembly
(28) To Oil Pan
(29) Pressure Control Valve(30) To Oil Pan
(31) Turbocharger
(32) Oil Gallery
(33) Timing Gear Train
17 65 4
3
2
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1
2
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