Daewoo NUBIRA, User Manual

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1F – 366 I ENGINE CONTROLS
DAEWOO V–121 BL4
Step No Yes Value(s) Action
7
1. Check the ignition system output with a spark
tester.
2. Inspect the spark plugs for the proper heat
range and gap.
3. Check for the proper operation of the ignition
controls.
Is the ignition system operating properly?
Go toStep 9 Go toStep 8
8 Repair or replace the ignition system components as
needed.
Is the repair complete? System OK
9
1. Connect the scan tool to the Data Link Con-
nector (DLC).
2. Road test the vehicle at the speed of the com-
plaint.
3. Monitor the long term fuel trim reading from the
scanner data stream.
Is the long term fuel trim reading above the value
specified?
150 counts Go to”Diagnos-
tic Aids for
DTC P0171”
Go toStep 10
10 Check the fuel system pressure.
Is the problem found? 41–47 psi
(284–325 kPa)
Go toStep 11 Go toStep 12
11 Repair or replace the fuel system components as
needed.
Is the repair complete? System OK
12
1. Inspect for carbon buildup inside the engine.
2. Remove the carbon with a top engine cleaner.
Follow the instructions supplied with the prod-
uct.
3. Check the basic engine parts such as the cam-
shaft, the cylinder head, the pistons, etc. for
excessive wear.
4. Replace any excessively worn parts.
Is the procedure complete?
Go toStep 13
13
1. Check the Exhaust Gas Recirculation (EGR)
valve for proper operation.
2. Check the air intake system for proper opera-
tion.
3. Check the Torque Converter Clutch (TCC) op-
eration and transaxle shift points.
4. Check the service bulletins for Programmable
Read–Only Memory (PROM) updates.
5. Check the cylinder compression.
6. Repair or replace any faulty components.
Are all checks and repairs complete?
System OK