ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-29
Excessive detona-
tion
(Engine makes con-
tinuously sharp
metallic knocks that
change with throttle
opening. Sounds
like pop corn pop-
ping.)Faulty spark plug Spark plugs in Section 6F1.
Loose connection of high-tension cord High-tension cords in Section 6F1.
Engine overheating Refer to “Overheating” section.
Clogged fuel filter (faulty fuel pump) or fuel
linesDiagnostic Flow Table B-1 or B-2.
Air inhaling from intake manifold or throttle
body gasket
Malfunctioning EGR valve (if equipped) EGR system in Section 6E1.
Poor performance of knock sensor, ECT sen-
sor or MAP sensorKnock sensor in Section 6, ECT sensor
or MAP sensor in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Faulty ECM
Excessive combustion chamber deposits Piston and cylinder head cleaning in
Section 6A1.
Engine has no
powerFaulty spark plug Spark plugs in Section 6F1.
Faulty ignition coil with ignitor Ignition coil in Section 6F1.
Leaks, loose connection or disconnection of
high-tension cordHigh-tension cords in Section 6F1.
Faulty knock sensor Knock sensor malfunction in this sec-
tion.
Clogged fuel hose or pipe Diagnostic Flow Table B-3.
Malfunctioning fuel pump Diagnostic Flow Table B-2.
Air inhaling from intake manifold gasket or
throttle body gasket
Engine overheating Refer to “Overheating” section.
Engine has no
powerMalfunctioning EGR valve (if equipped) EGR system inspection in Section 6E1.
Maladjusted accelerator cable play Accelerator cable play in Section 6E1.
Poor performance of TP sensor, ECT sensor
or MAP sensorTP sensor, ECT sensor or MAP sensor
in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Faulty ECM
Dragging brakes Trouble diagnosis in Section 5.
Slipping clutch Trouble diagnosis in Section 7C.
Low compression Previously outlined. Condition Possible Cause Correction
6-30 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Improper engine
idling or engine fails
to idleFaulty spark plug Spark plugs in Section 6F1.
Leaky or disconnected high-tension cord High-tension cords in Section 6F1.
Faulty ignition coil with ignitor Ignition coil in Section 6F1.
Fuel pressure out of specification Diagnostic Flow Table B-3.
Leaky manifold, throttle body, or cylinder
head gasket
Malfunctioning EGR valve (if equipped) EGR system in Section 6E1.
Faulty idle air control system Diagnostic Flow Table B-4.
Faulty evaporative emission control system EVAP control system in Section 6E1.
Faulty EGR system (if equipped) EGR system in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Poor performance of ECT sensor, TP sensor
or MAP sensorECT sensor, TP sensor or MAP sensor
in Section 6E1.
Faulty ECM
Loose connection or disconnection of vacuum
hoses
Malfunctioning PCV valve PCV system in Section 6E1.
Engine overheating Refer to “Overheating” section.
Low compression Previously outlined.
Excessive hydrocar-
bon (HC) emission
or carbon monox-
ide (CO)Faulty spark plug Spark plugs in Section 6F1.
Leaky or disconnected high-tension cord High-tension cords in Section 6F1.
Faulty ignition coil with ignitor Ignition coil assembly in Section 6F1.
Low compression Refer to “Low compression” section.
Lead contamination of three way catalytic
converterCheck for absence of filler neck restric-
tor.
Faulty evaporative emission control system EVAP control system in Section 6E1.
Fuel pressure out of specification Diagnostic Flow Table B-3.
Closed loop system (A/F feed back compen-
sation) fails
Faulty TP sensor
Poor performance of ECT sensor or MAP
sensorTP sensor in Section 6E1.
ECT sensor or MAP sensor in Section
6E1.
Faulty injector(s) Diagnostic Flow Table B-1
Faulty ECM
Engine not at normal operating temperature
Clogged air cleaner
Vacuum leaks
Excessive nitrogen
oxides (NOx) emis-
sionImproper ignition timing See section 6F1.
Lead contamination of catalytic converter Check for absence of filler neck restric-
tor.
Faulty EGR system (if equipped) EGR system in Section 6E1.
Fuel pressure out of specification Diagnostic Flow Table B-3.
Closed loop system (A/F feed back compen-
sation) fails
Faulty TP sensor
Poor performance of ECT sensor or MAP
sensorTP sensor in Section 6E1.
ECT sensor or MAP sensor in Section
6E1.
Faulty injector(s) Diagnostic Flow Table B-1
Faulty ECM Condition Possible Cause Correction
6-82 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 158°F or lower
–Engine coolant temp. : – 10 – 110°C, 14 – 230°F
4) Start engine and keep it at idle for 2 min. or more.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
6) If DTC is not detected at idle, consult usual driving based on information obtained in “Customer complaint
analysis” and “Freeze frame data check”.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
Engine under other than high revolution condition
Not on rough road
Engine speed changing rate (Below specified value)
Manifold absolute pressure changing rate (Below
specified value)
Throttle opening changing rate (Below specified
value)
Misfire rate per 200 or 1000 engine revolutions (how
much and how often crankshaft revolution speed
changes) is higher than specified valueEngine overheating
Vacuum leaks (air inhaling) from air intake system
Ignition system malfunction (spark plug(s), high-
tension cord(s), ignition coil assembly)
Fuel pressure out of specification
Fuel injector malfunction (clogged or leakage)
Engine compression out of specification
Valve lash (clearance) out of specification
Manifold absolute pressure sensor malfunction
Engine coolant temp. sensor malfunction
PCV valve malfunction
EVAP control system malfunction
EGR system malfunction
NOTE:
Among different types of random misfire, if misfire occurs at cylinders 1 and 4 or cylinders 3 and 2
simultaneously, it may not possible to reconfirm DTC by using the following DTC confirmation proce-
dure. When diagnosing the trouble of DTC P0300 (Random misfire detected) of the engine which is
apparently misfiring, even if DTC P0300 cannot be reconfirmed by using the following DTC confirma-
tion procedure, proceed to the following Diag. Flow Table.
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester.
CAUTION:
For iridium spark plugs, do not adjust air gap or clean.
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE
DIAG. FLOW
TABLE”.
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-83
2 Is there DTC other than Fuel system (DTC P0171/
P0172) and misfire (DTC P0300-P0304)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.
3 Check Ignition System.
1) Remove spark plugs and check them for;
Air gap : 1.0 – 1.1 mm (0.040 – 0.043 in.) See Fig. 1.
Carbon deposits/Insulator damage/Plug type
If abnormality is found, adjust, clean or replace.
2) Disconnect all injector connectors.
3) Connect spark plugs to high tension cords and then
ground spark plugs.
4) Crank engine and check that each spark plug sparks.
Are above check results satisfactory?Go to Step 4. Check ignition sys-
tem parts (Refer to
Section 6F1)
4 Check Fuel Pressure (Refer to Section 6E1 for details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge. See Fig. 2.
3) Check fuel pressure.
With fuel pump operating and engine at stop : 270 –
310 kPa, 2.7 – 3.1 kg/cm
2, 38.4 – 44.0 psi.
At specified idle speed : 270 – 310 kPa, 2.7 – 3.1 kg/
cm
2, 38.4 – 44.0 psi.
Is measured value as specified?Go to Step 5. Go to Diag. Flow
Table B-3 fuel
pressure check.
5 Check Fuel Injectors and Circuit.
1) Using sound scope (1) or such, check operating
sound of each injector (2) when engine is running.
Cycle of operating sound should very according to
engine speed. See Fig 3.
If no sound or an unusual sound is heard, check
injector circuit (wire or connector) or injector.
2) Turn ignition switch OFF and disconnect a fuel injec-
tor connector.
3) Check for proper connection to fuel injector at each
terminal. See Fig. 4.
4) If OK, then check injector resistance.
Injector Resistance : 11.3 – 13.8 ohm at 20°C (68°F)
5) Carry out steps 1) and 3) on each injector.
6) Check each injector for injected fuel volume referring
to Section 6E1. See Fig. 5.
Injected Fuel Volume : 43 – 47 cc/15 sec (1.45/1.51 –
1.58/1.65 US/Imp. oz/15 sec)
7) Check each injector for fuel leakage after injector
closed.
Fuel Leakage : Less than 1 drop/min.
Is check result in step 1) and 3) to 7) satisfactory?Go to Step 6. Check injector cir-
cuit or replace fuel
injector(s).
6 Check PCV Valve for clogging (See Section 6E1).
Is it in good condition?Go to Step 7. Replace PCV
valve. Step Action Yes No
6A1-4 ENGINE MECHANICAL (M13 ENGINE)
DIAGNOSIS
DIAGNOSIS TABLE
Refer to “ENGINE MECHANICAL DIAGNOSIS TABLE” in Sec-
tion 6.
COMPRESSION CHECK
Check compression pressure on all 4 cylinders as follows:
1) Warm up engine to normal operating temperature.
2) Stop engine after warming up.
3) Remove air cleaner assembly (1), resonator (2) and hoses.
Refer to “AIR CLEANER ASSEMBLY AND RESONATOR”.
4) Remove cylinder head upper cover (1).
5) Disconnect ignition coil couplers (1).
6) Remove ignition coil assemblies (2) with high-tension cord
(3).
7) Remove all spark plugs.
8) Disconnect fuel injector wires (4) at the coupler.NOTE:
After warming up engine, place transmission gear shift
lever in “Neutral” (shift selector lever to “P” range for A/T
model), and set parking brake and block drive wheels.
ENGINE MECHANICAL (M13 ENGINE) 6A1-5
9) Install special tools (compression gauge) into spark plug
hole.
Special tool
(A) : 09915-64510-001
(B) : 09915-64510-002
(C) : 09915-64530
(D) : 09915-67010
10) Disengage clutch (1) (to lighten starting load on engine) for
M/T vehicle, and depress accelerator pedal (2) all the way to
make throttle fully open.
11) Crank engine with fully charged battery, and read the highest
pressure on compression gauge.
Compression pressure
12) Carry out Steps 9) through 11) on each cylinder to obtain 4
readings.
NOTE:
For measuring compression pressure, crank engine at
least 250 rpm by using fully charged battery.
If measured compression pressure is lower than limit
value, check installation condition of special tool. If it
is properly installed, possibility is compression pres-
sure leakage from where piston ring and valve contact.
Standard 1400 kPa
(14.0 kg/cm
2, 199.0 psi)
Limit 1100 kPa
(11.0 kg/cm
2, 156.0 psi)
Max. difference between
any two cylinders100 kPa
(1.0 kg/cm
2, 14.2 psi)
6A1-6 ENGINE MECHANICAL (M13 ENGINE)
13) After checking, install spark plugs and ignition coil assem-
blies (1) with high-tension cord (2).
14) Connect ignition coil couplers (3).
15) Connect fuel injector wires(4) at the coupler.
16) Check cylinder head upper cover gasket for deterioration
and then install it into groove of cylinder head upper cover
(1) securely.
17) Install cylinder head upper cover with gasket on to cylinder
head cover.
18) Install air cleaner assembly, resonator and hoses referring to
“AIR CLEANER ASSEMBLY AND RESONATOR”.
ENGINE VACUUM CHECK
The engine vacuum that develops in the intake line is a good indi-
cator of the condition of the engine. The vacuum checking proce-
dure is as follows :
1) Warm up engine to normal operating temperature.
2) Stop engine and turn off the all electric switches.
3) Remove cap (1) from intake manifold.
NOTE:
After warming up engine, be sure to place transmission
gear shift lever in “Neutral” (shift selector lever to “P”
range for A/T model), and set parking brake and block
drive wheels.
6A1-14 ENGINE MECHANICAL (M13 ENGINE)
6) Remove oil level gauge (1).
7) Disconnect PCV hose (2) from PCV valve (3) and release
harness clamp.
8) Remove cylinder head cover mounting bolts in such order as
indicated in figure.
9) Remove cylinder head cover (1) with cylinder head cover
gasket (2) and spark plug hole gasket (3).
INSTALLATION
1) Install new spark plug hole gaskets (1) and new cylinder
head cover gasket (2) to cylinder head cover (3) as shown in
figure.
2) Remove oil, old sealant, and dust from sealing surface on
cylinder head and cover. After cleaning, apply sealant “A” to
the following point.
Cylinder head gasket (1) sealing surface area (2) as shown.
“A” : Sealant 99000-31150