Daewoo Nubira User Manual page 567

1F – 364IENGINE CONTROLS
LACK OF POWER, SLUGGISHNESS, OR SPONGINESS
The engine delivers less than expected power. There
is little or no increase in speed when the accelerator
pedal is partially applied.
Step
1 Were the Important Preliminary Checks performed?
2
1. Verify the customer's complaint.
2. Compare the performance of the customer's
vehicle with a similar unit.
Does the problem exist?
3
1. Inspect the air filter for excessive contamina-
tion.
2. Replace the air filter as needed.
3. Check the transaxle shift pattern and downshift
operation.
Does the transaxle operate properly?
4 Check the fuel system pressure.
Is the fuel system pressure within specifications?
5 Repair the transaxle as needed.
Is the repair complete?
6 Repair the fuel system as needed.
Is the repair complete?
7 Check for a restricted fuel filter or contaminated fuel.
Is the problem found?
8 Repair or replace any components as needed.
Is the repair complete?
9
1. Check the ignition system output for all of the
cylinders using a spark tester.
2. Check for proper ignition control operation.
Is the ignition system operating properly?
10
1. With the engine at normal operating tempera-
ture, connect a vacuum gauge to a vacuum
port on the intake manifold.
2. Operate the engine at 1,000 rpm.
3. Record the vacuum reading.
4. Increase the engine speed to 2,500 rpm.
5. Note the vacuum reading at a steady 2,500
rpm.
Does the vacuum decrease more than the value
specified?
11 Repair or replace any ignition system components
as needed.
Is the repair complete?
12 Inspect the exhaust system for restrictions and dam-
aged or collapsed pipes.
Is the problem found?
13 Repair or replace any components as needed.
Is the repair complete?
Action Value(s) Yes
Go toStep 2
Go toStep 3
Go toStep 4
41–47 psi Go toStep 7
(284–325 kPa)
System OK
System OK
Go toStep 8
System OK
Go toStep 10
10 kPa Go toStep 12
(3 in. Hg)
System OK
Go toStep 13
System OK
No
Go to"Impor-
tant Preliminary
Checks"
System OK
Go toStep 5
Go toStep 6
Go toStep 9
Go toStep 11
Go toStep 15
Go toStep 14
DAEWOO V–121 BL4