Downloaded from www.Manualslib.com manuals search engine 6-20 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Visual inspection
Visually check following parts and systems.
INSPECTION ITEM REFERRING SECTION
Engine oil – level, leakage Section 0B
Engine coolant – level, leakage Section 0B
Fuel – level, leakage Section 0B
A/T fluid – level, leakage Section 0B
Air cleaner element – dirt, clogging Section 0B
Battery – fluid level, corrosion of terminal
Water pump belt – tension, damage Section 0B
Throttle cable – play, installation
Section 6E Vacuum hoses of air intake system – disconnection, looseness,
deterioration, bend
Connectors of electric wire harness – disconnection, friction
Fuses – burning Section 8
Parts – installation, bolt – looseness
Parts – deformation
Other parts that can be checked visually
Also check following items at engine start, if possible
Malfunction indicator lamp – operation Section 6
Charge warning lamp – operation Section 6H
Engine oil pressure warning lamp – operation Section 8 (Section 6 for pressure check)
Engine coolant temp. meter – operation Section 8
Fuel level meter – operation Section 8
Tachometer, if equipped – operation
Abnormal air being inhaled from air intake system
Exhaust system – leakage of exhaust gas, noise
Other parts that can be checked visually
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Engine basic inspection
This check is very important for troubleshooting when ECM has detected no DTC and no abnormality has been
found in visual inspection.
Follow the flow table carefully.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check battery voltage.
Is it 11 V or more?Go to Step 3. Charge or replace battery.
3 Is engine cranked? Go to Step 4. Go to “Diagnosis” in Sec-
tion 6G.
4 Does engine start? Go to Step 5. Go to Step 9.
5 Check idle speed as follows :
1) Warm up engine to normal operating temp.
2) Shift transmission to neutral position for M/T
(“P” position for A/T).
3) All of electrical loads are switched off.
4) Check engine idle speed with scan tool.
See Fig. 1.
Is it 650 – 750 r/min (700 – 800 r/min. for A/T
vehicle)?Go to Step 6. Go to “Engine Diagnosis
Table”.
6 Is SUZUKI scan tool available? Go to Step 8. Go to Step 7.
7 Check ignition timing as follows :
1) Connect test switch terminal (2) of monitor
coupler (1) to ground. See Fig. 2.
2) Remove air cleaner bolt and crips and shift
air cleaner position to observe ignition tim-
ing.
3) Using timing light (1), check initial ignition
timing.
See Fig. 4.
Is it 5° ± 3° BTDC at specified idle speed?Go to “Engine Diagnosis
Table”.Check ignition control
related parts referring to
Section 6F.
8 Check ignition timing as follows :
1) Select “MISC” mode on SUZUKI scan tool
and fix ignition timing to initial one. See Fig.
3.
2) Remove air cleaner bolt and crips and shift
air cleaner position to observe ignition tim-
ing.
3) Using timing light (1), check initial ignition
timing. See Fig. 4.
Is it 5° ± 3° BTDC at specified idle speed?Go to “Engine Diagnosis
Table”.Check ignition control
related parts referring to
Section 6F.
9 Check immobilizer system malfunction as fol-
lows (if equipped) :
1) Check immobilizer indicator lamp or MIL
(malfunction indicator lamp) for flashing.
Is it flashing when ignition switch is turned to
ON position?Go to “Diagnosis” in Sec-
tion 8G.Go to Step 10.
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[A] Fig. 1 for Step 5 / [B] Fig. 2 for Step 7 / [C] Fig. 3 for Step 810 Check fuel supply as follows :
1) Check to make sure that enough fuel is filled
in fuel tank.
2) Turn ON ignition switch for 2 seconds and
then OFF. See Fig. 5.
Is fuel return pressure (returning sounds) felt
from fuel feed hose (1) when ignition switch is
turned ON?Go to Step 12. Go to Step 11.
11 Check fuel pump for operating.
1) Was fuel pump operating sound heard from
fuel filler for about 2 seconds after ignition
switch ON and stop?Go to “Diag. Flow Table
B-3”.Go to “Diag. Flow Table
B-2”.
12 Check ignition spark as follows :
1) Disconnect injector couplers.
2) Remove spark plugs and connect them to
high tension cords.
3) Ground spark plugs.
4) Crank engine and check if each spark plug
sparks.
Is it in good condition?Go to Step 13. Go to “Ignition Spark Test”
in Section 6F.
13 Check fuel injector for operation as follows :
1) Install spark plugs and connect injector con-
nectors.
2) Using sound scope (2), check operating
sound of each injector (3) when cranking
engine. See Fig. 6.
Was injector operating sound heard from all
injectors?Go to “Engine Diagnosis
Table”.Go to “Diag. Flow Table
B-1”. Step Action Yes No
[B] : When not using SUZUKI scan tool :
[C] : When using SUZUKI scan tool
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[D] Fig. 4 for Step 7 or 8 / [E] Fig. 5 for Step 10 / [F] Fig. 6 for Step 13
Engine diagnosis table
Perform troubleshooting referring to following table when ECM has no DTC and no abnormality found in visual
inspection and engine basic inspection previously.
Condition Possible Cause Reference Item
Hard Starting
(Engine cranks OK)Faulty ignition coil Ignition coil assembly in Section 6F.
Faulty CMP sensing rotor or CKP sensing
rotorCMP sensing rotor or CKP sensing
rotor inspection in Section 6E.
Faulty idle air control system Diagnostic Flow Table B-4
Faulty ECT sensor, TP sensor, CKP sen-
sor, CMP sensor or MAP sensorECT sensor, TP sensor, CKP sensor,
CMP sensor or MAP sensor in Sec-
tion 6E.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty fuel injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning PCV system PCV system in Section 6E.
Low compression Compression check in Section 6A1.
Improper valve lash Valve lash in Section 6A1.
Improper valve timing Timing chain and chain tensioner in
Section 6A1.
Compression leak from valve seat Valves and cylinder head in Section
6A1.
Sticky valve stem Valves and cylinder head in Section
6A1.
Weak or damaged valve springs Valves and cylinder head in Section
6A1.
Compression leak at cylinder head gasket Valves and cylinder head in Section
6A1.
Sticking or damaged piston ring Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Worn piston, ring or cylinder Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
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Engine has no power
Engine overheating Refer to “Overheating” of this table.
Faulty ignition coil Ignition coil assembly in Section 6F.
Faulty knock sensor Knock sensor malfunction in this sec-
tion.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty injector Diagnostic Flow Table B-1
Faulty TP sensor, ECT sensor or MAP
sensorTP sensor, ECT sensor or MAP sen-
sor in Section 6E.
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E.
Maladjusted accelerator cable play Accelerator cable adjustment in Sec-
tion 6E.
Low compression Previously outlined.
Dragging brakes Diagnosis table in Section 5.
Slipping clutch Diagnosis table in Section 7C.
Improper engine idling
or engine fails to idleFaulty ignition coil Ignition coil assembly in Section 6F.
Engine overheating Refer to “Overheating” of this table.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty idle air control system Diagnostic Flow Table B-4
Faulty evaporative emission control sys-
temEVAP control system in Section 6E.
Faulty injector Diagnostic Flow Table B-1
Faulty ECT sensor, TP sensor or MAP
sensorECT sensor, TP sensor or MAP sen-
sor in Section 6E.
Malfunctioning PCV system PCV system in Section 6F.
Faulty ECM Inspection of ECM and its circuit in
this section.
Faulty EGR system (if equipped) EGR system in Section 6E.
Low compression Previously outlined.
Engine hesitates
(Momentary lack of
response as the accel-
erator is depressed.
Can occur at all vehicle
speeds.
Usually most severe
when first trying to
make the vehicle move,
as from a stop sign.)Faulty ignition coil Ignition coil assembly in Section 6F.
Engine overheating Refer to “Overheating” of this table.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty injector Diagnostic Flow Table B-1
Faulty TP sensor, ECT sensor or MAP
sensorTP sensor, ECT sensor or MAP sen-
sor in Section 6E.
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E.
Low compression Previously outlined.
Surges
(Engine power variation
under steady throttle or
cruise.
Feels like the vehicle
speeds up and down
with no change in the
accelerator pedal.)Faulty ignition coil or high-tension cord Ignition coil assembly or high-tension
cords in Section 6F.
Variable fuel pressure Diagnostic Flow Table B-3
Faulty MAP sensor MAP sensor in Section 6E.
Faulty injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E. Condition Possible Cause Reference Item
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Excessive detonation
(The engine makes
sharp metallic knocks
that change with throt-
tle opening.
Sounds like pop corn
popping.)Engine overheating Refer to “Overheating” of this table.
Faulty spark plug Spark plugs in Section 6F.
Clogged fuel filter and fuel lines Diagnostic Flow Table B-3
Malfunctioning EGR valve (if equipped) EGR system in Section 6E.
Poor performance of knock sensor, ECT
sensor or MAP sensorKnock sensor in this section, ECT
sensor or MAP sensor in Section 6E.
Faulty injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Excessive combustion chamber deposits Piston and cylinder head in Section
6A1.
Overheating
Inoperative thermostat Thermostat in Section 6B.
Faulty A/C condenser fan motor or its cir-
cuitA/C condenser fan control system
check in Section 6E.
Loose or slip water pump belt ITEM1-1 Drive belt inspection and
change in Section 0B.
Poor water pump performance Water pump in Section 6B.
Clogged or leaky radiator Radiator in Section 6B.
Improper engine oil grade ITEM1-3 Engine oil and oil filter
change in Section 0B.
Clogged oil filter or oil strainer Oil pressure check in Section 6A1.
Poor oil pump performance Oil pressure check in Section 6A1.
Dragging brakes Diagnosis Table in Section 5.
Slipping clutch Diagnosis Table in Section 7C.
Blown cylinder head gasket Valves and cylinder head in Section
6A1.
Poor gasoline mileage
Faulty ignition coil Ignition coil assembly in Section 6F.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty TP sensor, ECT sensor or MAP
sensorTP sensor, ECT sensor or MAP sen-
sor in Section 6E.
Faulty injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E.
High idle speed Refer to item “Improper Engine Idle
Speed” previously outlined.
Low compression Previously outlined.
Poor valve seating Valves and cylinder head in Section
6A1.
Dragging brakes Diagnosis Table in Section 5.
Slipping clutch Diagnosis Table in Section 7C.
Thermostat out of order Thermostat in Section 6B.
Improper tire pressure Refer to Section 3F. Condition Possible Cause Reference Item
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Excessive engine oil
consumptionSticky piston ring Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Worn piston and cylinder Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Worn piston ring groove and ring Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Improper location of piston ring gap Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Worn or damaged valve stem seal Valves and cylinder head in Section
6A1.
Worn valve stem Valves and cylinder head in Section
6A1.
Low oil pressure
Improper oil viscosity ITEM1-3 Engine oil and oil filter
change in Section 0B.
Malfunctioning oil pressure switch Oil pressure switch in Section 8.
Clogged oil strainer Oil pan and oil pump strainer in Sec-
tion 6A1.
Functional deterioration of oil pump Oil pump in Section 6A1.
Worn oil pump relief valve Oil pump in Section 6A1.
Excessive clearance in various sliding
partsRefer to Section 6A1.
Engine noise
See NOTE below.Improper valve lash Valve lash in Section 6A1.
Worn valve stem and guide Valves and cylinder head in Section
6A1.
Weak or broken valve spring Valve springs in Section 6A1.
Warped or bent valve Valves and cylinder head in Section
6A1.
Loose camshaft housing bolts Camshaft in Section 6A1.
Worn piston, ring and cylinder bore Pistons and cylinders in Section 6A1.
Worn crankpin bearing Crankpin and connecting rod bearing
in Section 6A1.
Worn crankpin Crankpin and connecting rod bearing
in Section 6A1.
Loose connecting rod nuts Connecting rod in Section 6A1.
Low oil pressure Previously outlined.
Worn crankshaft journal bearing Main bearings, Crankshaft and cylin-
der block in Section 6A1.
Worn crankshaft journal Main bearings, Crankshaft and cylin-
der block in Section 6A1.
Loose lower crankcase (bearing cap) bolts Main bearings, Crankshaft and cylin-
der block in Section 6A1.
Excessive crankshaft thrust play Main bearings, Crankshaft and cylin-
der block in Section 6A1. Condition Possible Cause Reference Item
NOTE:
Before checking the mechanical noise, make sure that :
Ignition timing is properly adjusted.
Specified spark plug is used.
Specified fuel is used.
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Condition Possible Cause Reference Item
Excessive hydrocar-
bon (HC) emission or
Excessive carbon mon-
oxide (CO) emissionFaulty ignition coil Ignition coil assembly in Section 6F.
Fuel pressure out of specification Diagnostic Flow Table B-3
Lead contamination of three way catalytic
converterMaintenance in Section 6K.
Malfunctioning PCV system PCV system in Section 6E.
Faulty EVAP control system EVAP control system in Section 6E.
Closed loop system (A/F feed back com-
pensation) fails
–Faulty TP sensor
–Faulty ECT sensor or MAP sensor
–Faulty oxygen sensorCheck oxygen sensor output voltage.
Refer to DTC P0130 (No.14) Table in
this section.
Faulty injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Low compression Previously outlined.
Excessive nitrogen
oxides (NOx) emissionFuel pressure out of specification Diagnostic Flow Table B-3
Lead contamination of three way catalytic
converterMaintenance in Section 6K.
Closed loop system (A/F feed back com-
pensation) fails
–Faulty TP sensor
–Faulty ECT sensor or MAP sensor
–Faulty oxygen sensorCheck oxygen sensor output voltage
Refer to DTC P0130 (No.14) Table in
this section.
Faulty injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Faulty EGR system (if equipped) EGR system in Section 6E.