2003 DAEWOO MATIZ fuel

ENGINE CONTROLS 1F–285
DAEWOO M-150 BL2
Hard Start (Cont’d)
StepActionValue(s)YesNo
23
1. Check for the proper valve timing.
2. Check the cylinder compression.
3. Inspect the pushrods, the rocker arms, the valve
springs, and the camshaft lobes for excessive
wear.
4. Inspect the intake manifold and the exhaust
manifold passages for casting flash.
Is the problem found?
–
Go to Step 24Go to Step 25
24Repair or replace any components as needed.
Is the repair complete?–System OK–
25
Check the idle air control valve operation. Repair or
replace components as needed.
Is the repair complete?
–
System OK
–
26
Check the throttle position sensor circuit for proper
operation. Repair or replace components as needed.
Is the repair complete?
–
System OK
–
27Repair the fuel system as needed.
Is the repair complete?–System OK–
28
1. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?
–
System OK
–

1F–286 ENGINE CONTROLS
DAEWOO M-150 BL2
SURGES OR CHUGGLES
Definition: Engine power variation under steady throttle
or cruise. Feels like the vehicle speeds up and slows
down with no change in the accelerator pedal position.Important: Make sure the driver understands A/C com-
pressor operation as described in the owner’s manual.
The speedometer reading and the speed reading on the
scan tool should be equal.
Before diagnosing the symptom, check service bulletins
for updates.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
Connect the scan tool to the Data Link Connector
(DLC).
Does the oxygen sensor (O2S) respond quickly to
different throttle positions?
–
Go to Step 4Go to Step 3
3
1. Check the O2S for silicone or other contaminants
from fuel or use of improper Room Temperature
Vulcanizing (RTV) sealant.
2. Replace the contaminated O2S.
Is the repair complete?
–
System OK
–
4
1. Drive the vehicle at the speed of the complaint.
2. Monitor the long term fuel trim reading using the
scan tool.
Is the long term fuel trim reading within the value
specified?
–20–25%Go to Step 7Go to Step 5
5
Is the long term fuel trim reading below the value
specified?
–20%
Go to
“Diagnostic Aids
for DTC P0172”
Go to Step 6
6
Is the long term fuel trim reading above the value
specified?
25%
Go to
“Diagnostic Aids
for DTC P0171”
–
7
Check the fuel system pressure while the condition
exists.
Is the fuel system pressure within specifications?
380 kPa
(55 psi)
Go to Step 8Go to Step 17
8Check the in-line fuel filter.
Is the filter dirty or plugged?–Go to Step 18Go to Step 9
9Perform an injector diagnosis.
Did the injector diagnosis pinpoint the problem?–Go to Step 19Go to Step 10
10
1. Check for proper ignition voltage output using a
spark tester.
2. Inspect the spark plugs for cracks, wear, improper
gap, burned electrodes, or heavy deposits.
Is the problem found?
–
Go to Step 11Go to Step 12
11
Repair or replace any ignition system components
as needed.
Is the repair complete?
–
System OK
–
12
1. Inspect the ECM grounds for being clean, tight,
and in their proper locations.
2. Inspect the vacuum lines for kinks or leaks.
Is the problem found?
–
Go to Step 13Go to Step 14

ENGINE CONTROLS 1F–287
DAEWOO M-150 BL2
Surges or Chuggles (Cont’d)
StepActionValue(s)YesNo
13
Repair the electrical connections or the vacuum
lines as needed.
Is the repair complete?
–
System OK
–
14Check the generator output voltage.
Is the generator voltage within the value specified?12–16 V
Go to Step 16Go to Step 15
15Repair the generator.
Is the repair complete?–System OK–
16
1. Check for intermittent Electric Exhaust Gas
Recirculation (EEGR) valve operation.
2. Repair or replace any components as needed.
Is the repair complete?
–
System OK
–
17Repair the fuel system as needed.
Is the repair complete?–System OK–
18Replace the fuel filter.
Is the repair complete?–System OK–
19Replace the leaking or restricted fuel injectors.
Is the repair complete?–System OK–

1F–288 ENGINE CONTROLS
DAEWOO M-150 BL2
LACK OF POWER, SLUGGISHNESS, OR SPONGINESS
Definition: The engine delivers less than expected pow-
er. There is little or no increase in speed when the accel-
erator pedal is partially applied.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Verify the customer’s complaint.
2. Compare the performance of the customer’s
vehicle with a similar unit.
Does the problem exist?
–
Go to Step 3System OK
3
1. Inspect the air filter for excessive contamination.
2. Replace the air filter as needed.
3. Check the transaxle shift pattern and down shift
operation.
Does the transaxle operate properly?
–
Go to Step 4Go to Step 5
4Check the fuel system pressure.
Is the fuel system pressure within specifications?380 kPa
(55 psi)
Go to Step 7Go to Step 6
5Repair the transaxle as needed.
Is the repair complete?–System OK–
6Repair the fuel system as needed.
Is the repair complete?–System OK–
7Check for a restricted fuel filter or contaminated fuel.
Is the problem found?–Go to Step 8Go to Step 9
8Repair or replace any components as needed.
Is the repair complete?–System OK–
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?
–
Go to Step 10Go to Step 11
10
1. With the engine at normal operating temperature,
connect a vacuum gauge to a vacuum port on the
intake manifold.
2. Operate the engine at 1000 rpm.
3. Record the vacuum reading.
4. Increase the engine speed to 2500 rpm.
5. Note the vacuum reading at a steady 2500 rpm.
Does the vacuum decrease more than the value
specified?
10 kPa
(3 in Hg)
Go to Step 12Go to Step 15
11
Repair or replace any ignition system components
as needed.
Is the repair complete?
–
System OK
–
12
Inspect the exhaust system for restrictions and
damaged or collapsed pipes.
Is the problem found?
–
Go to Step 13Go to Step 14
13Repair or replace any components as needed.
Is the repair complete?–System OK–
14
1. Check the cylinder compression and valve timing.
2. Inspect the camshaft for excessive wear.
Is the problem found?
–
Go to Step 15Go to Step 16

1F–290 ENGINE CONTROLS
DAEWOO M-150 BL2
DETONATION/SPARK KNOCK
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Fill the fuel tank with a known good grade of
gasoline that has the octane rating of the value
specified.
2. Reevaluate the vehicle’s performance.
Does the detonation problem still exist?
91 octaneGo to Step 3System OK
3
1. Inspect for low engine coolant level.
2. Check for restricted airflow to the radiator or
restricted coolant flow.
3. Check for a faulty thermostat.
4. Check for an incorrect coolant solution.
Is the problem found?
–
Go to Step 4Go to Step 5
4
Repair or replace any cooling system components
as needed.
Is the repair complete?
–
System OK
–
5
1. Check the engine coolant temperature using the
scan tool.
2. Replace the Engine Coolant Temperature (ECT)
sensor if the resistance is not within specifications
as listed in the Diagnostic Aids for diagnostic
trouble code P0118.
Is the problem found?
–
Go to Step 6Go to Step 7
6
Replace the ECT sensor or repair the circuit as
needed.
Is the repair complete?
–
System OK
–
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 to Step 9Go to Step 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 Connector
(DLC).
2. Road test the vehicle at the speed of the
complaint.
3. Monitor the long term fuel trim reading from the
scanner data stream.
Is the long term fuel trim reading above the value
specified?
25%
Go to
“Diagnostic Aids
for DTC P0171”
Go to Step 10
10Check the fuel system pressure.
Is the problem found?380 kPa
(55 psi)
Go to Step 11Go to Step 12
11
Repair or replace the fuel system components as
needed.
Is the repair complete?
–
System OK
–

1F–292 ENGINE CONTROLS
DAEWOO M-150 BL2
HESITATION, SAG, STUMBLE
Definition: Momentary lack of response as the accelera-
tor is pushed down. This can occur at any vehicle speed.
It is usually the most severe when first trying to make the
vehicle move, as from a stop. Hesitation, sag, or
stumble may cause the engine to stall if severe enough.Important: Before diagnosing this condition, check ser-
vice bulletins for PROM updates.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Check the fuel system pressure. If the pressure is
not within the value specified, service the fuel
system as needed.
2. Inspect the Throttle Position (TP) sensor for
binding or sticking. The TP sensor voltage should
increase at a steady rate as the throttle is moved
toward Wide Open Throttle (WOT).
Is the problem found?
380 kPa
(55 psi)
Go to Step 3Go to Step 4
3Repair or replace any components as needed.
Is the repair complete?–System OK–
4
1. Check the Manifold Absolute Pressure (MAP)
sensor response and accuracy.
2. Inspect the fuel for water contamination.
3. Check the Evaporative Emission (EVAP) Canister
Purge System for proper operation.
Is the problem found?
–
Go to Step 5Go to Step 6
5Repair or replace any components as needed.
Is the repair complete?–System OK–
6
1. Disconnect all of the fuel injector harness
connectors.
2. Connect an injector test light between the
harness terminals of each fuel injector.
3. Note the test light while cranking the engine.
Does the test light blink on all connectors?
–
Go to Step 8Go to Step 7
7
1. Repair or replace the faulty fuel injector drive
harness, the connector, or the connector terminal.
2. If the connections and the harnesses are good,
replace the Engine Control Module (ECM).
Is the repair complete?
–
System OK
–
8
Measure the resistance of each fuel injector.
Is the fuel injector resistance within the value
specified (the resistance will increase slightly at
higher temperatures)?
11.6–12.4 ΩGo to Step 10Go to Step 9
9
Replace any of the fuel injectors with a resistance
that is out of specifications.
Is the repair complete?
–
System OK
–
10Perform an injector diagnosis.
Is the problem found?–Go to Step 11Go to Step 12
11Replace any restricted or leaking fuel injectors.
Is the repair complete?–System OK–
12
Check the fuel system pressure after a cold start or
during moderate or full throttle acceleration.
Is the fuel pressure within specifications?
380 kPa
(55 psi)
Go to Step 14Go to Step 13

ENGINE CONTROLS 1F–293
DAEWOO M-150 BL2
Hesitation, Sag, Stumble (Cont’d)
StepActionValue(s)YesNo
13
Repair the restriction in the fuel system or replace
the faulty fuel pump.
Is the repair complete?
–
System OK
–
14
1. Check for faulty ignition wires.
2. Inspect for fouled spark plugs.
3. Check the ignition system output on each cylinder
with a spark tester.
Is the problem found?
–
Go to Step 15Go to Step 16
15
Repair or replace any ignition components as
needed.
Is the repair complete?
–
System OK
–
16
1. Check the generator output voltage.
2. Repair or replace the generator if the generator
output is less than the value specified.
3. Check the Electric Exhaust Gas Recirculation
(EEGR) valve operation.
Are all checks and needed repairs complete?
–
System OK
–

1F–294 ENGINE CONTROLS
DAEWOO M-150 BL2
CUTS OUT, MISSES
Definition: Steady pulsation or jerking that follows en-
gine speed, usually more pronounced as engine load in-creases. The exhaust has a steady spitting sound at idle
or low speed.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
Check the ignition system voltage output for all of
the cylinders using a spark tester.
Is spark present on all of the cylinders?
–
Go to Step 3
Go to “Ignition
System Check”
3
1. Inspect the spark plugs for excessive wear,
insulation cracks, improper gap, or heavy
deposits.
2. Check the resistance of the ignition wires.
Replace any ignition wires that have a resistance
greater than the value specified.
Is the problem found?
30000 ΩGo to Step 4Go to Step 5
4Repair or replace any components as needed.
Is the repair complete?–System OK–
5
With the engine running, spray the ignition wires with
a fine water mist to check for arcing and shorting to
ground.
Is the problem found?
–
Go to Step 6Go to Step 7
6Replace the ignition wires.
Is the repair complete?–System OK–
7
1. Perform a cylinder compression test.
2. If the compression is low, repair the engine as
needed.
3. Inspect for proper valve timing, bent pushrods,
worn rocker arms, broken or weak valve springs,
and worn camshaft lobes.
4. Inspect the intake manifold and the exhaust
manifold passages for casting flash.
Is the problem found?
–
Go to Step 8Go to Step 9
8Repair or replace any components as needed.
Is the repair complete?–System OK–
9
1. Check the fuel system for a plugged in-line fuel
filter.
2. Check the fuel system for low fuel pressure. If the
fuel pressure is below the value specified, service
the fuel system as needed.
3. Inspect for contaminated fuel.
Is the problem found?
380 kPa
(55 psi)
Go to Step 10Go to Step 11
10Repair or replace any components as needed.
Is the repair complete?–System OK–
11
1. Disconnect all of the fuel injector harness
connectors at the fuel injectors.
2. Connect an injector test light to the harness
terminals of each fuel injector connector.
3. Note the test light while cranking the engine for
each fuel injector.
Does the test light blink for all of the fuel injectors?
–
Go to Step 13Go to Step 12