Daewoo NUBIRA, Owner'S Manual, Page: 161 / 744

ENGINE CONTROLS 1F – 37
DAEWOO V–121 BL4
ENGINE CRANKS BUT WILL NOT RUN
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
3. By performing a compression test, it can be deter-
mined if the engine has the mechanical ability to
run.
9. It is important to check for the presence of spark
from all of the ignition wires. If spark is present from
one to three of the ignition coil terminals, the crank-
shaft position (CKP) sensor is OK.
19. In checking the powertrain control module
(PCM)/engine control module (ECM) outputs for the
electronic spark timing signal, it recommended to
use an oscilloscope to view the varying voltage sig-
nals. In measuring these outputs with a voltmeter,
intermittent errors may occur that cannot be seen
by a voltmeter.
35. This step checks for proper operation of the PCM/
ECM’s control of the fuel pump circuit.
59. This step checks for a ground signal being supplied
by the PCM/ECM to operate the fuel injectors. If
there is no ground present during the cranking of
the engine, and the fuel injector wiring is OK, the
PCM/ECM is at fault.
Engine Cranks But Will Not Run
CAUTION : Use only electrically insulated pliers when handling ignition wires with the engine running to prevent
an electrical shock.
CAUTION : Do not pinch or restrict nylon fuel lines to avoid damage that could cause a fuel leak, resulting in
possible fire or personal injury.
Important : If engine cranks but will not start, make sure fuel cut–off switch has not been tripped.
Step Action Value(s) Yes No
1 Perform an On–Board Diagnostic (OBD II) System
Check.
Is the system check complete? Go to Step 2 Go to ”On–
Board Diagnos-
tic System
Check”
2 Crank the engine.
Does the engine start and continue to run? System OK Go to Step 3
3 Perform a cylinder compression test.
Is the cylinder compression for all of the cylinders at
or above the value specified? 689 kPa (100
psi)
Go toStep 7 Go toStep 4
4 Inspect the timing belt alignment.
Is the timing belt in alignment? Go toStep 6 Go toStep 5
5 Align or replace the timing belt as needed.
Is the repair complete? Go toStep 2
6 Repair the internal engine damage as needed.
Is the repair complete? Go toStep 2
7 Inspect the fuel pump fuse.
Is the problem found? Go toStep 8 Go toStep 9
8 Replace the fuse.
Is the repair complete? Go toStep 2
9 Check for the presence of spark from all of the igni-
tion wires while cranking the engine.
Is spark present from all of the ignition wires? Go toStep 34 Go toStep 10
10
1. Measure the resistance of the ignition wires.
2. Replace any of the ignition wire(s) with a resist-
ance above the value specified.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?
30,000
W
Go toStep 2 Go toStep 11