Daewoo MATIZ Service Manual page 396

1F – 298 ENGINE CONTROLS
Rough, Unstable, or Incorrect Idle, Stalling (Cont'd)
Step
Is the long term fuel trim reading below the value
specified?
12
Is the long term fuel trim reading above the value
13 specified?
1. Disconnect all of the fuel injector harness
connectors at the fuel injectors.
2. Connect an injector test light between the
14
harness terminals of each fuel injector connector.
3. Note the test light while cranking the engine.
Does the test light blink for all of the fuel injectors?
1. Repair or replace the faulty injector drive circuit
harness, the connector, or the connector
terminals as needed.
2. If the harness, the connectors, and the terminals
15
are OK, replace the Engine Control Module
(ECM).
Is the repair complete?
Measure the resistance of each of the fuel injectors.
Is the resistance within the value specified (the
16
resistance will increase slightly at higher
temperatures)?
Replace any fuel injectors with a resistance that is
out of specifications.
17
Is the repair complete?
Perform an injector diagnosis.
18
Is the problem found?
Replace any leaking or restricted fuel injectors.
19
Is the repair complete?
1. With the engine OFF, disconnect the fuel
pressure regulator vacuum hose.
2. Thoroughly inspect the fuel pressure regulator
20
vacuum port and the fuel pressure regulator
vacuum hose for the presence of fuel.
Is the problem found?
Replace the fuel pressure regulator as needed.
21
Is the repair complete?
1. Check the ignition system output voltage for all of
the cylinders using a spark tester.
2. Inspect the spark plugs for excessive wear,
insulation cracks, improper gap, or heavy
deposits.
22
3. Inspect the ignition wires for cracking, hardness,
or improper connections.
4. Replace any ignition wires with a resistance over
the value specified.
Is the problem found?
Repair or replace any ignition system components
as needed.
23
Is the repair complete?
Action Value(s) Yes
Go to
"Diagnostic Aids
–20% for DTC P0172"
Go to
"Diagnostic Aids
25% for DTC P0171"
–
Go to Step 16
–
System OK
11.6–12.4 Ω
Go to Step 18
–
System OK
–
Go to Step 19
–
System OK
–
Go to Step 21
–
System OK
30000 Ω
Go to Step 23
–
System OK
No
Go to Step 13
–
Go to Step 15
–
Go to Step 17
–
Go to Step 20
–
Go to Step 22
–
Go to Step 24
–
DAEWOO M-150 BL2