Opel Frontera UBS. Manual - part 2095

6C–3

ENGINE FUEL

D

Adhere to all Notices and Cautions.

All gasoline engines are designed to use only unleaded
gasoline. Unleaded gasoline must be used for proper
emission control system operation.
Its use will also minimize spark plug fouling and extend
engine oil life. Using leaded gasoline can damage the
emission control system and could result in loss of
emission warranty coverage.
All cars are equipped with an Evaporative Emission
Control System. The purpose of the system is to minimize
the escape of fuel vapors to the atmosphere.

Fuel Metering

The Engine Control Module (ECM) is in complete control
of this fuel delivery system during normal driving
conditions.
The intake manifold function, like that of a diesel, is used
only to let air into the engine. The fuel is injected by
separate injectors that are mounted over the intake
manifold.
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load and speed changes, which the MAP
sensor converts to a voltage output.
This sensor generates the voltage to change
corresponding to the flow of the air drawn into the engine.
The changing voltage is transformed into an electric
signal and provided to the ECM.
With receipt of the signals sent from the MAP sensor,
Intake Air Temperature sensor and others, the ECM
determines an appropriate fuel injection pulse width
feeding such information to the fuel injector valves to
effect an appropriate air/fuel ratio.
The Multiport Fuel Injection system utilizes an injection
system where the injectors turn on at every crankshaft
revolution.  The ECM controls the injector on time so that
the correct amount of fuel is metered depending on
driving conditions.
Two interchangeable “O” rings are used on the injector
that must be replaced when the injectors are removed.
The fuel rail is attached to the top of the intake manifold
and supplies fuel to all the injectors.
Fuel is recirculated through the rail continually while the
engine is running. This removes air and vapors from the
fuel as well as keeping the fuel cool during hot weather
operation.
The fuel pressure control valve that is mounted on the fuel
rail maintains a pressure differential across the injectors
under all operating conditions. It is accomplished by
controlling the amount of fuel that is recirculated back to
the fuel tank based on engine demand.
See Section “Driveability and Emission” for more
information and diagnosis.

6C–4

ENGINE FUEL

Fuel Filter

Fuel Filter and Associated Parts

041RW014

Legend

(1) Fuel Filler Cap
(2) Fuel Hose

(3) Fuel Filter Fixing Bolt
(4) Fuel Filter

Removal

CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system
for loose connection or leakage. For the fuel system
diagnosis, see Section “Driveability and Emission”.

1. Disconnect battery ground cable.
2. Remove Fuel filler cap(1).
3. Disconnect fuel hoses(2) from fuel filter on both

engine side and fuel tank side.

4. Fuel filter fixing bolt(3).

D

Remove the fuel filter fixing bolt(3) on fuel filter
holder.

5. Remove fuel filter(4).

Inspection

1. Replace the fuel filter if the fuel leaks from fuel filter

body or if the fuel filter body itself is damaged.

2. Replace the filter if it is clogged with dirt or sediment.
3. Check the drain of receive rubber and if it is clogged

with dust, clean it up with air.

6C–5

ENGINE FUEL

Installation

1. Install the fuel filter in the proper direction.
2. Install fuel filter holder fixing bolt.
3. Connect fuel hoses on engine side(1) and fuel tank

side(2).

041RW001

4. Install fuel filler cap
5. Connect the battery ground cable.

Inspection

After installation, start engine and check for fuel leakage.

In–Tank Fuel Filter

The filter is located on the lower end of fuel pickup tube in
the fuel tank. It prevents dirt from entering the fuel pipe
and also stops water unless the filter is completely
submerged in the water. It is a self cleaning type, not
requiring scheduled maintenance. Excess water and
sediment in the tank restricts fuel supply to the engine,
resulting in engine stoppage. In such a case, the tank
must be cleaned thoroughly.

Fuel Pump Flow Test

If reduction of fuel supply is suspected, perform the
following checks:

1. Make sure that there is fuel in the tank.
2. With the engine running, check the fuel feed pipe and

hose from fuel tank to injector for evidence of
leakage. Retighten, if pipe or hose connection is
loose. Also, check pipes and hoses for squashing or
clogging.

3. Insert the hose from fuel feed pipe into a clean

container, and check for fuel pump flow rate.

4. Connect the pump relay terminals with a jumper

wire(1) as shown and start the fuel pump to measure
delivery.

140RW002

CAUTION: Never generate sparks when connecting
a jumper wire.

Delivery

Delivery

15 seconds

0.38 liters minimum

If the measure value is out of standard, conduct the
pressure test.

Pressure test

For the pressure test to the fuel system, see Section 6E
“Fuel Control System”.

6C–6

ENGINE FUEL

Fuel Pump

Fuel Pump and Associated Parts

035RW047

Removal

CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system
for loose connection or leakage. For the fuel system
diagnosis, see Section “Driveability and Emission”.

1. Disconnect battery ground cable.
2. Loosen fuel filler cap.
3. Drain fuel.

Tighten drain plug to the specified torque after
draining fuel.

Torque: 20 N·m (2.0 Kg·m/14 lb ft) — M8

4. Remove fuel tank assembly(1). Refer to “Fuel Tank

Removal” in this section.

5. Remove fuel pump (FP) assembly(2) fixing screws

and remove the FP assembly.

NOTE: After removing FP, cover fuel tank to prevent any
dust entering.

Installation

1. Install FP assembly(2).
2. Install fuel tank assembly(1). Refer to “Fuel Tank

Installation”.

3. Fill the tank with fuel and tighten fuel filler cap.
4. Connect battery ground cable.