1. No.1 cylinder
2. No.2 cylinder
3. No.3 cylinder
123
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-3
GENERAL INFORMATION
STATEMENT ON CLEANLINESS AND CARE
An automobile engine is a combination of many machined, honed,
polished and lapped surfaces with tolerances that are measured in
the thousands of an millimeter (ten thousands of an inch).
Accordingly, when any internal engine parts are serviced, care and
cleanliness are important.
Throughout this section, it should be understood that proper clean-
ing and protection of machined surfaces and friction areas is part
of the repair procedure. This is considered standard shop practice
even if not specifically stated.
A liberal coating of engine oil should be applied to friction areas
during assembly to protect and lubricate the surfaces on initial op-
eration.
Whenever valve train components, pistons, piston rings, con-
necting rods, rod bearings, and crankshaft journal bearings are
removed for service, they should be retained in order.
At the time of installation, they should be installed in the same
locations and with the same mating surfaces as when removed.
Battery cables should be disconnected before any major work is
performed on the engine.
Failure to disconnect cables may result in damage to wire har-
ness or other electrical parts.
Throughout this manual, the four cylinders of the engine are iden-
tified by numbers; No.1 (1), No.2 (2) and No.3 (3) counted from
crankshaft pulley side to flywheel side.
GENERAL INFORMATION ON ENGINE SERVICE
THE FOLLOWING INFORMATION ON ENGINE SERVICE
SHOULD BE NOTED CAREFULLY, AS IT IS IMPORTANT IN PRE-
VENTING DAMAGE, AND IN CONTRIBUTING TO RELIABLE EN-
GINE PERFORMANCE.
When raising or supporting engine for any reason, do not use a
jack under oil pan. Due to small clearance between oil pan and
oil pump strainer, jacking against oil pan may cause it to be bent
against strainer resulting in damaged oil pick-up unit.
It should be kept in mind, while working on engine, that 12-volt
electrical system is capable of violent and damaging short cir-
cuits.
When performing any work where electrical terminals can be
grounded, ground cable of the battery should be disconnected at
battery.
Any time the air cleaner, throttle body or intake manifold is re-
moved, the intake opening should be covered. This will protect
against accidental entrance of foreign material which could follow
intake passage into cylinder and cause extensive damage when
engine is started.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-5
FUEL PRESSURE RELIEF PROCEDURE
CAUTION:
This work must not be done when engine is hot. If done so,
it may cause adverse effect to catalyst.
After making sure that engine is cold, release fuel pressure as fol-
lows.
1) Place transmission gear shift lever in “Neutral” (Shift selector le-
ver to “P” range for A / T model), set parking brake, and block
drive wheels.
2) Remove relay box cover.
3) Disconnect fuel pump relay (1) from relay box (2).
4) Remove fuel filler cap to release fuel vapor pressure in fuel tank
and then reinstall it.
5) Start engine and run it till it stops for lack of fuel. Repeat cranking
engine 2-3 times for about 3 seconds each time to dissipate fuel
pressure in lines. Fuel connections are now safe for servicing.
6) Upon completion of servicing, connect fuel pump relay to relay
box and install relay box cover.
FUEL LEAKAGE CHECK PROCEDURE
After performing any service on fuel system, check to make sure
that there are no fuel leakages as follows.
1) Turn ON ignition switch for 2 seconds (to operate fuel pump) and
then turn it OFF.
Repeat this (ON and OFF) 3 or 4 times and apply fuel pressure
to fuel line. (till fuel pressure is felt by hand placed on fuel feed
hose.)
2) In this state, check to see that there are no fuel leakages from
any part of fuel system.
6-12 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
CUSTOMER PROBLEM INSPECTION FORM (EXAMPLE)
User name:Model:VIN:
Date of issue:Date Reg.Date of problem:Mileage:
PROBLEM SYMPTOMS
Difficult Starting
No cranking
No initial combustion
No combustion
Poor starting at
(cold warm always)
OtherPoor Driveability
Hesitation on acceleration
Back fire /After fire
Lack of power
Surging
abnormal knocking
Other
Poor Idling
Poor fast idle
Abnormal idling speed
(High Low) ( r / min.)
Unstable
Hunting ( r / min. to r / min.)
OtherEngine Stall when
Immediately after start
Accel. pedal is depressed
Accel. pedal is released
Load is applied
A/C Electric load P/S
Other
Other
OTHERS:
VEHICLE / ENVIRONMENTAL CONDITION WHEN PROBLEM OCCURS
Environmental Condition
Weather
Temperature
Frequency
RoadFair Cloudy Rain Snow Always Other
Hot Warm Cool Cold (F/C) Always
Always Sometimes ( times/ day, month) Only once Under certain condition
Urban Suburb Highway Mountainous (Uphill Downhill) Tarmacadam Gravel
Other
Vehicle Condition
Engine
conditionCold Warming up phase Warmed up Always Other at starting
Immediately after start Racing without load Engine speed ( r / min.)
Vehicle
conditionDuring driving: Constant speed Accelerating Decelerating
Right hand corner Left hand corner When shifting (Lever position ) At stop
Vehicle speed when problem occurs ( km/h, Mile / h) Other
Malfunction indicator
lamp conditionAlways ON Sometimes ON Always OFF Good condition
Diagnostic troubleFirst check:No code Malfunction code ( )g
codeSecond check:No code Malfunction code ( )
NOTE:
The above form is a standard sample. It should be modified according to conditions characteristic of each
market.
6-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC
NO.DETECTING ITEMDETECTING CONDITION
(DTC will set when detecting:)MIL
P0335Crankshaft position sensor
circuit malfunctionNo signal during engine running1 driving cycle
P0340Camshaft position sensor
circuit malfunctionNo signal for 2 sec. during engine cranking1 driving cycle
P0420Catalyst system efficiency
below threshold
Output waveforms of HO2S-1 and HO2S-2
are similar.
(Time from output voltage change of HO2S-1
to that of HO2S-2 is shorter than
specification.)
2 driving cycles
P0443EVAP Purge control valve
circuit malfunctionPurge control valve circuit is open or shorted
to ground2 driving cycles
P0480Radiator fan control circuit
malfunctionRadiator cooling fan relay terminal voltage is
low when cooling temp. is lower than
specification
2 driving cycles
P0500Vehicle speed sensor
malfunctionNo signal while running in “D” range or during
fuel cut at decelerating2 driving cycles
P0505Idle control system malfunction
Throttle opening change is small as compared
with electrically live time. Throttle valve opening
is not within its target range with CTP switch ON
or drive voltage exists though ECM (PCM) is not
outputting ISC drive command.
1 driving cycle
P0510Closed throttle position switch
malfunctionSwitch does not change from ON to OFF
(or from OFF to ON) even when vehicle speed
reaches over (or below) specification.
2 driving cycle
P1250Early Fuel Evaporation Heater
Circuit MalfunctionHeater monitor terminal voltage is higher than
specified value when EFE OFF or it is lower
than specified value when EFE ON.
2 driving cycles
P1450Barometric pressure sensor
circuit malfunctionBarometric pressure is lower or higher than
specification. (or sensor malfunction)1 driving cycle
P1451Barometric pressure sensor
performance problem
Difference between manifold absolute
pressure (MAP sensor value) and
barometric pressure (barometric pressure
sensor value) is larger than specification
during cranking.
2 driving cycles
P1500Starter signal circuit
malfunctionStarter signal is not inputted from engine
cranking till its start and after or it is always
inputted
2 driving cycles
P1510ECM (PCM) backup power
source malfunctionNo backup power after starting engine1 driving cycle
6-20 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
ENGINE BASIC INSPECTION
This check is very important for troubleshooting when ECM (PCM) has detected no DTC and no abnormality has
been found in visual inspection.
Follow the flow table carefully.
STEP
ACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check battery voltage.
Is it 11 V or more?Go to Step 3.Charge or replace
battery.
3Is engine cranked?Go to Step 4.Go to “DIAGNOSIS”
in Section 6G.
4Does engine start?Go to Step 5.Go to Step 7.
5Check 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 800 – 900 r / min.?Go to Step 6.Go to “ENGINE
DIAGNOSIS TABLE”.
6Check ignition timing as follows.
1) Select “MISC” mode on SUZUKI scan tool and
fix ignition timing to initial one. See Fig. 2.
2) Using timing light (1), check initial ignition timing.
See Fig. 3.
Is it 5 ± 3 BTDC at specified idle speed?Go to “ENGINE
DIAGNOSIS TABLE”.Check ignition control
related parts referring
to Section 6F.
7Check immobilizer system malfunction as follows.
1) Check immobilizer indicator lamp for flashing.
Is it flashing when ignition switch is turned to ON
position?Go to “DIAGNOSIS” in
Section 8A.Go to Step 8.
8Check 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. 4.
Is fuel return pressure (returning sounds) felt from fuel
feed hose (1) when ignition switch is turned ON?Go to Step 10.Go to Step 9.
9Check 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”.
10Check ignition spark as follows.
1) Disconnect injector coupler.
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 11.Go to “DIAGNOSIS”
in Section 6F.
11Check fuel injector for operation as follows.
1) Install spark plugs and connect injector
connectors.
2) Check that fuel is injected out in conical shape
from fuel injector when cranking.
Is it in good condition?Go to “ENGINE
DIAGNOSIS TABLE”.Go to “DIAG. FLOW
TABLE B-1”.
6-22 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
ENGINE DIAGNOSIS TABLE
Perform troubleshooting referring to following table when ECM (PCM) has detected no DTC and no abnormality
has been found in visual inspection and engine basic inspection previously.
Condition
Possible CauseReferring Item
Hard Starting
(Engine cranks OK)Ignition system out of order
Faulty spark plug
Leaky high-tension cord
Loose connection or disconnection of high-
tension cords or lead wires
Faulty ignition coil
Fuel system out of order
Dirty or clogged fuel hose or pipe
Malfunctioning fuel pump
Air inhaling from intake manifold gasket or
throttle body gasket
Fuel injector resistor malfunction
Engine and emission control system out of
order
Faulty idle control system
Faulty ECT sensor or MAP sensor
Faulty ECM (PCM)
Low compression
Poor spark plug tightening or faulty gasket
Compression leak from valve seat
Sticky valve stem
Weak or damaged valve springs
Compression leak at cylinder head gasket
Sticking or damaged piston ring
Worn piston, ring or cylinder
Others
Malfunctioning PCV valve
Spark plugs in Section 6F
High-tension cords in Section 6F
High-tension cords in Section 6F
Ignition coil in Section 6F
Diagnostic Flow Table B-3
Diagnostic Flow Table B-3
Fuel injector resistor in Section 6E1
Diagnostic Flow Table P0505
ECT sensor or MAP sensor in
Section 6E1
Compression check in Section
6A
Spark plugs in Section 6F
Valves inspection in Section 6A
Valves inspection in Section 6A
Valve springs inspection in
Section 6A
Cylinder head inspection in
Section 6A
Cylinders, pistons and piston rings
inspection in Section 6A
Cylinders, pistons and piston rings
inspection in Section 6A
PCV system in Section 6E1
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-23
ConditionPossible CauseReferring Item
Low oil pressureImproper oil viscosity
Malfunctioning oil pressure switch
Clogged oil strainer
Functional deterioration of oil pump
Worn oil pump relief valve
Excessive clearance in various sliding partsEngine oil and oil filter change in
Section 0B
Oil pressure switch inspection in
Section 8
Oil pan and oil pump strainer
cleaning in Section 6A
Oil pump in Section 6A
Oil pump in Section 6A
Engine noise
Note: Before
checking mechanical
noise, make sure
that:
Specified spark
plug in used.
Specified fuel is
used.Valve noise
Improper valve lash
Worn valve stem and guide
Weak or broken valve spring
Warped or bent valve
Piston, ring and cylinder noise
Worn piston, ring and cylinder bore
Connecting rod noise
Worn rod bearing
Worn crank pin
Loose connecting rod nuts
Low oil pressure
Crankshaft noise
Low oil pressure
Worn bearing
Worn crankshaft journal
Loose bearing cap bolts
Excessive crankshaft thrust play
Valve lash in Section 6A
Valves inspection in Section 6A
Valve springs inspection in
Section 6A
Valves inspection in Section 6A
Pistons and cylinders inspection
in Section 6A
Crank pin and connecting rod
bearing inspection in Section 6A
Crank pin and connecting rod
bearing inspection in Section 6A
Connecting rod installation in
Section 6A
Previously outlined
Previously outlined
Crankshaft and bearing
inspection in Section 6A
Crankshaft and bearing
inspection in Section 6A
Crankshaft inspection in
Section 6A
Crankshaft thrust play inspection
in Section 6A
6-32 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
SCAN TOOL DATA DEFINITIONS
FUEL SYSTEM (FUEL SYSTEM STATUS)
Air / fuel ratio feedback loop status displayed as either
open or closed loop. Open indicates that ECM (PCM)
ignores feedback from the exhaust oxygen sensor.
Closed indicates final injection duration is corrected
for oxygen sensor feedback.
CALC LOAD (CALCULATED LOAD VALUE, %)
Engine load displayed as a percentage of maximum
possible load. Value is calculated mathematically us-
ing the formula: actual (current) intake air volume
maximum possible intake air volume x 100%.
COOLANT TEMP.
(ENGINE COOLANT TEMPERATURE, C, F)
It is detected by engine coolant temp. sensor
SHORT FT B1 (SHORT TERM FUEL TRIM, %)
Short term fuel trim value represents short term
corrections to the air / fuel mixture computation. A val-
ue of 0 indicates no correction, a value greater than
0 means an enrichment correction, and a value less
than 0 implies an enleanment correction.
LONG FT B1 (LONG TERM FUEL TRIM, %)
Long term fuel trim Value represents long term correc-
tions to the air / fuel mixture computation. A value of 0
indicates no correction, a value greater than 0 means
an enrichment correction, and a value less than 0 im-
plies an enleanment correction.
MAP (INTAKE MANIFOLD ABSOLUTE
PRESSURE, kPa, inHg)
It is detected by manifold absolute pressure sensor and
used (among other things) to compute engine load.
ENGINE SPEED (rpm)
It is computed by reference pulses from crankshaft
position sensor.
VEHICLE SPEED (km / h, MPH)
It is computed based on pulse signals from vehicle
speed sensor.
IGNITION ADVANCE
(IGNITION TIMING ADVANCE FOR NO.1
CYLINDER, )
Ignition timing of NO.1 cylinder is commanded by
ECM (PCM). The actual ignition timing should be
checked by using the timing light.
INTAKE AIR TEMP. (C, F)
It is detected by intake air temp. sensor and used to
determine the amount of air passing into the intake
manifold as air density varies with temperature.
MAF (MASS AIR FLOW RATE, gm / s, lb / min)
It represents total mass of air entering intake manifold
which is computed based on signals from MAP sen-
sor, IAT sensor, TP sensor, etc.
THROTTLE POS
(ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is fully closed position,
throttle opening is indicated as 0% and 100% full open
position.
OXYGEN SENSOR B1 S1
(HEATED OXYGEN SENSOR-1, V)
It indicates output voltage of HO2S-1 installed on ex-
haust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2
(HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on ex-
haust pipe (post-catalyst). It is used to detect catalyst
deterioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM (PCM) internal pa-
rameter which indicates the ECM (PCM) requested
idle. If the engine is not running, this number is not valid.
TP SENSOR VOLT (THROTTLE POSITION
SENSOR OUTPUT VOLTAGE, V)
The Throttle Position Sensor reading provides throttle
valve opening information in the form of voltage.
INJ PULSE WIDTH
(FUEL INJECTION PULSE WIDTH, msec.)
This parameter indicates time of the injector drive
(valve opening) pulse which is output from ECM
(PCM) (but injector drive time of NO.1 cylinder for
multiport fuel injection).
IAC FLOW DUTY (IDLE AIR (SPEED) CONTROL
DUTY, %)
This parameter indicates opening of the throttle valve
in terms of percentage to opening controllable by the
ISC actuator.
TOTAL FUEL TRIM (%)
The value of Total Fuel Trim is obtained by putting val-
ues of short Term Fuel Trim and Long Term Fuel Trim
together. This value indicates how much correction is
necessary to keep the air / fuel mixture stoichiomet-
rical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage in-
putted from main relay to ECM (PCM).