Opel Frontera UBS. Manual - part 2127

6E–81

ENGINE DRIVEABILITY AND EMISSIONS

Engine Cranks But Will Not Run

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

Check the 15 A ignition coil fuse, the 15 A engine fuse,
and the 30 A PCM fuse.

Was a fuse blown?

—

Go to 

Step 3

Go to 

Step 4

3

Check for a short to ground and replace the fuse.

Is the action complete?

—

Verify repair

—

4

1. Ignition “OFF,” install a fuel pressure gauge at the

test fitting on the fuel supply line in the engine
compartment.  (Use a shop cloth to absorb any fuel
leakage while making the connection.)

2. Ignition “ON,” observe the fuel pressure.

Is the fuel pressure within the specified values, and
does it hold steady?

285-376 kPa

(43-55 psi)

Go to 

Step 6

Go to 

Step 5

5

Is any fuel pressure indicated?

—

Go to 

Fuel

System

Electrical Test

Go to 

Fuel

System

Diagnosis

6

Install an injector switch box to the injector test
connector, and attempt to operate the injector.

Did the fuel pressure drop when the injector is
operated?

—

Go to 

Step 7

Go to 

Step 12

7

Install an injector test light at the #2 cylinder injector
harness connector.

Does the light blink when the engine is cranked?

—

Go to 

Step 8

Go to 

Step 18

8

1. Ignition “ON.”
2. While the coil connectors are disconnected, touch

each coil connector’s ignition feed terminal with a
grounded test light (the ignition feed wire is black
with orange tracer).

Did the test light illuminate?

—

Go to 

Step 10

Go to 

Step 9

9

Repair the open ignition feed circuit.

Is the action complete?

—

Verify repair

—

10

While the coil connectors are disconnected, touch
each connector’s secondary ground terminal with a
test light to B+.  (The ground wires are black.)

Did the test light illuminate at each coil connector?

—

Go to 

Step 12

Go to 

Step 11

11

Repair the open secondary ground circuit.

Is the action complete?

—

Verify repair

—

12

1. Test the fuel for contamination.
2. If a problem is found, clean the fuel system and

correct the contaminated fuel condition as
necessary.  Replace the fuel filter and replace any
injectors that are not delivering fuel (see Injector
Balance Test).

Was a problem found?

—

Verify repair

Go to 

Step 13

6E–82

ENGINE DRIVEABILITY AND EMISSIONS

Engine Cranks But Will Not Run

  (Cont'd)

Step

No

Yes

Value(s)

Action

13

1. Remove any ignition coil and install a spark tester at

the spark plug end of the coil.

2. Observe the tester while the engine is cranking.

Was a crisp, blue spark observed?  Only one or two
sparks followed by no result is considered the same as
“No Spark.”

—

Go to 

Step 15

Go to 

Step 14

14

Replace the ignition coil, and return to Step 13 to test
the remaining coils.

Is the action complete?

—

Verify repair

—

15

Repeat Step 13 for each coil.  Remove only one coil at a
time, and reinstall each coil on its spark plug after
testing, but do not refasten coils with screws at this
time.

After all coils have passed the spark test, does the
engine start?

—

Refasten all

coils with

their screws

Go to 

Step 16

16

1. Remove the spark plugs from all cylinders.
2. Visually inspect the spark plug electrodes.
3. Replace any spark plugs with loose or missing

electrodes or cracked insulators.

Did your inspection reveal any spark plugs exhibiting
excessive fouling?

—

Correct the

fouling

condition

Go to 

Step 17

17

Refer to 

Engine Mechanical Diagnosis to diagnose the

following conditions:

D

Faulty or incorrect camshaft drive belts

D

Leaking or sticky valves or rings

D

Excessive valve deposits

D

Loose or worn rocker arms

D

Weak valve springs

D

Incorrect valve timing

D

Leaking head gasket

Is the action complete?

—

Verify repair

Go to 

Step 19

18

Observe the “Engine Speed” data display on the scan
tool while cranking the engine.

Is the engine RPM indicated?  (If the scan tool is
normally powered from the cigarette lighter socket, and
if the scan tool display goes blank while cranking the
engine, it will be necessary to power the scan tool
directly from the vehicle battery.)

—

Go to 

Step 19

Go to 

Step 28

19

1. Disconnect the 7-pin gray connector at the rear of

the air filter beneath the point where the air duct
attaches to the MAF sensor.

2. Ignition “ON.”
3. Using a test light connected to ground, probe the

ignition terminal at the PCM (female) side of the
7-pin connector.

Is the test light “ON?”

—

Go to 

Step 20

Go to 

Step 26

6E–83

ENGINE DRIVEABILITY AND EMISSIONS

Engine Cranks But Will Not Run

  (Cont'd)

Step

No

Yes

Value(s)

Action

20

1. At the PCM (female) side of the connector, connect

a test light between the ignition + terminal and one
of the injector driver circuits at the same connector.

2. Ignition “ON.”
3. Observe the test light, and repeat the test for each

injector driver circuit.

Did the test light stay on when checking any of the 6
injector driver circuits?

—

Go to 

Step 21

Go to 

Step 23

21

1. Ignition “OFF,” disconnect the PCM.
2. Ignition “ON,” observe the test light.

Is the test light “ON?”

—

Go to 

Step 22

Go to 

Step 27

22

Locate and repair the short to ground in the injector
driver circuit.

Is the action complete?

—

Verify repair

—

23

1. Using the same test location as in step 20, connect

a test light between the ignition terminal and one of
the driver circuits.

2. Crank the engine and observe the test light.
3. Repeat for each injector driver circuit.

Did the light blink during the test for each circuit?

—

Go to 

Step 25

Go to 

Step 24

24

Check for an open injector driver circuit.

Was a problem found?

—

Verify repair

Go to 

Step 27

25

1. At the injector (male) side of the gray connector,

connect an ohmmeter between the ignition pin and
one of the driver circuit pins.

2. Check for continuity in the circuit.
3. Repeat for each injector circuit.  The readings

should be approximately equal to the  specified
value for injector resistance.

Was a problem found?

12.5 ohms

Verify repair

Go to 

Step 8

26

Repair the ignition feed circuit.

Is the action complete?

—

Verify repair

—

27

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed. Refer to 

UBS 98model year Immobilizer

Workshop Manual.

Is the action complete?

—

Verify repair

—

28

1. Raise the vehicle and disconnect the CKP sensor

harness.

2. Ignition “ON.”
3. With a test light to ground, probe the harness

ignition feed terminal.

Did the light illuminate?

—

Go to 

Step 30

Go to 

Step 29

29

Check the ignition feed wire between the sensor and
the PCM for a short to ground or open circuit.

Is the action complete?

—

Verify repair

—

6E–84

ENGINE DRIVEABILITY AND EMISSIONS

Engine Cranks But Will Not Run

  (Cont'd)

Step

No

Yes

Value(s)

Action

30

1. Ignition “ON.”
2. At the CKP harness connector, connect a test light

between the ignition and ground terminals.

Did the light illuminate?

—

Go to 

Step 32

Go to 

Step 31

31

Check the sensor ground circuit for an open or short to
voltage.

Is the action complete?

—

Verify repair

—

32

Check the signal circuit between the sensor and the
PCM for a short to ground, short to voltage, or an open.

Was a problem found?

—

Verify repair

Go to 

Step 33

33

Replace the CKP sensor.

Is the action complete?

—

Verify repair

Go to 

Step 27