Daewoo Nubira User Manual page 579

1F – 376IENGINE CONTROLS
Fuel ignites in the intake manifold, or in the exhaust
system, making a loud popping noise.
Important : Before diagnosing the symptom, check ser-
vice bulletins for updates.
Step
1 Were the Important Preliminary Checks performed?
2
1. Inspect for crossed or crossfiring ignition wires.
2. Check the ignition system output voltage for all
cylinders using a spark tester.
3. Inspect the spark plugs for excessive wear,
burned electrodes, improper gap, or heavy de-
posits..
Is the problem found?
3 Repair or replace any ignition system components
as needed.
Is the repair complete?
4
1. Check the fuel system operation.
2. Check the fuel injectors by performing an injec-
tor diagnosis.
Is the problem found?
5 Repair or replace any fuel system components as
needed.
Is the repair complete?
6
1. Inspect the Exhaust Gas Recirculation (EGR)
gasket for a leak or a loose fit.
2. Check the EGR valve for proper operation.
3. Inspect the intake manifold and the exhaust
manifold for a casting flash.
Is the problem found?
7 Repair or replace any components as needed.
Is the repair complete?
8
1. Inspect the timing belt for proper installation
and tension.
2. Check the engine compression.
3. Inspect the intake manifold gasket and the ex-
haust manifold gasket for leaks.
4. Check for sticking or leaking valves.
5. Repair or replace any components as needed.
Are all checks and corrections complete?
BACKFIRE
Action Value(s) Yes
Go toStep 2
Go toStep 3
System OK
Go toStep 5
System OK
Go toStep 7
System OK
System OK
No
Go to"Impor-
tant Preliminary
Checks"
Go toStep 4
Go toStep 6
Go toStep 8
DAEWOO V–121 BL4