INSPECTION
| IMPORTANT | After warming-up, engine becomes very hot. Be careful not to burn yourself during measurement. |
After warming-up the engine, turn the ignition switch to OFF.
Make sure that the battery is fully charged.
Release the fuel pressure.
Remove all the spark plugs.
Fully open the throttle valve.
Check the starter motor for satisfactory performance and operation.
Hold the compression gauge tight against the spark plug hole.
Note. When using a screw-in type compression gauge, the screw (put into cylinder head spark plug hole) should be less than 18 mm (0.71 in) long.
Crank the engine by means of the starter motor, and read the maximum value on the gauge when the pointer is steady.
Scheme 21
Perform at least two measurements per cylinder, and make sure that the values are correct.
Compression (350 RPM and fully open throttle)
Standard
1,020 - 1,275 kPa (10.4 - 13.0 kgf/cm 2, 148 - 185 psi)
Difference between cylinders
49 kPa (0.5 kgf/cm 2 , 7 psi) or less
Before checking the idle speed, check the following
Ensure the air cleaner element is free from clogging, ignition timing is correct, spark plugs are in good condition, and hoses are connected properly.
Ensure the malfunction indicator light does not illuminate.
Idle the engine.
Stop the engine, and turn the ignition switch to OFF.
When using Vehicle Diagnostic Interface, refer to the following.
Connect the Vehicle Diagnostic Interface to data link connector.
Scheme 22
- Data link connector
Turn the ignition switch to ON, and start the Vehicle Diagnostic Interface.
Select {Each System Check} in the Main Menu.
Select {Engine} in the Selection Menu.
Select {Current Data Display & Save} in the Engine Control System Diagnosis.
Select {Data Display} in the Data Display Menu.
Start the engine, and read engine idle speed.
When using the tachometer (Secondary pick-up type)
Attach the pick-up clip to No. 1 cylinder spark plug cord.
Start the engine, and read engine idle speed.
Scheme 23
Note. This ignition system provides simultaneous ignition for #1 and #2 plugs. It must be noted that some tachometers may register twice that of actual engine speed.
Check the idle speed when unloaded. (With headlights, heater fan, rear defroster, radiator fan, A/C, etc. OFF)
Idle speed [No load and gears in "N" or "P" range]
650+/-100 RPM
Check the idle speed when loaded. (Turn the A/C switch to "ON" and operate the compressor for at least one minute before measurement.)
Idle speed [A/C "ON" and gears in "N" or "P" range]
850+/-100 RPM
Note. Idle speed cannot be adjusted manually, because the idle speed is automatically adjusted. If the idle speed is out of specifications, refer to General Diagnosis Table under " ".
| IMPORTANT | After warming-up, engine becomes very hot. Be careful not to burn yourself at measurement. |
Idle the engine.
To check the ignition timing, connect a timing light to #1 cylinder spark plug cord, and illuminate the timing mark with the timing light.
Start the engine and check the ignition timing at the following idle speed.
Ignition timing [BTDC/RPM]
MT
10°+/-8°/650
AT
15°+/-8°/700
Scheme 24
If the timing is not correct, check the ignition control system.
Idle the engine.
Disconnect the brake vacuum hose from the intake manifold, and then install the vacuum gauge.
Keep the engine at the idle speed and read the vacuum gauge indication.
By observing the gauge needle movement, the internal condition of the engine can be diagnosed as described below.
Scheme 25
Vacuum pressure (at idling, A/C "OFF")
Less than - 60.0 kPa (- 450 mmHg, - 17.72 inHg)
| Diagnosis of engine condition by measurement of intake manifold vacuum | |
|---|---|
| Vacuum gauge indication | Possible engine condition |
| 1. Needle is steady but lower than normal position. This tendency becomes more evident as engine temperature rises. | Air leakage around intake manifold gasket, disconnection or damage of vacuum hose |
| 2. When engine speed is reduced slowly from higher speed, needle stops temporarily when it is lowering or becomes steady above normal position. | Exhaust pressure is too high, or exhaust system is clogged. |
| 3. Needle intermittently drops to position lower than normal position. | Leakage around cylinder |
| 4. Needle drops suddenly and intermittently from normal position. | Valve anchoring |
| 5. When engine speed is gradually increased, needle begins to vibrate rapidly at certain speed, and then vibration increases as engine speed increases. | Weak or broken valve springs |
| 6. Needle vibrates above and below normal position in narrow range. | Defective ignition system |
DIAGNOSIS PROCEDURE
Disconnect the ground cable from battery.
Scheme 26
Remove the generator from bracket.
Disconnect the connector from oil pressure switch.
Remove the pressure switch from cylinder block.
Connect the oil pressure gauge hose to cylinder block.
Connect the battery ground cable to battery.
Scheme 27
Start the engine, and measure oil pressure.
Scheme 28
Oil pressure
Standard
88 kPa (0.9 kg/cm 2 , 13 psi) or more at 800 RPM
294 kPa (3.0 kg/cm 2 , 43 psi) or more at 5,000 RPM
| IMPORTANT | If the oil pressure is out of specification, check oil pump, oil filter and lubrication line. If the oil pressure warning light is turned to ON but oil pressure is within specification, replace the oil pressure switch. |
Note. The specified value is based on an engine oil temperature of 80°C (176°F).
After measuring the oil pressure, install the oil pressure switch.
Tightening torque
25 Nm (2.5 kgf-m, 18.1 ft -lb)
| WARNING | Before removing the fuel pressure gauge, release fuel pressure. |
Note. When the fuel pressure is out of specification, check or replace the pressure regulator and pressure regulator vacuum hose.
Release the fuel pressure.
Open the fuel filter flap lid, and remove the fuel filler cap.
Disconnect the fuel delivery hose from fuel damper, and connect a fuel pressure gauge.
Scheme 29
Connect the connector of fuel pump relay.
Scheme 30
Start the engine.
Measure the fuel pressure while disconnecting pressure regulator vacuum hose from intake manifold.
Fuel pressure
Standard: 284 - 314 kPa (2.9 - 3.2 kg/cm 2 , 41 - 46 psi)
After connecting the pressure regulator vacuum hose, measure the fuel pressure.
Fuel pressure
Standard: 206 - 235 kPa (2.1 - 2.4 kg/cm 2 , 30 - 34 psi)
Note. The fuel pressure gauge registers 10 to 20 kPa (0.1 to 0.2 kg/cm 2 , 1 to 3 psi) higher than standard values during high-altitude operations.
| IMPORTANT | Inspection and adjustment of valve clearance should be performed while engine is cold. |
Set the vehicle on a lift.
Lift-up the vehicle.
Remove the under cover.
Lower the vehicle.
Disconnect the ground cable from battery.
Scheme 31
Remove the timing belt cover (LH).
Scheme 32
When inspecting #1 and #3 cylinders
Disconnect the spark plug cords from spark plugs RH side.
Disconnect the PCV hose from rocker cover (RH).
Remove the bolts, then remove the rocker cover (RH).
When inspecting #2 and #4 cylinders
Disconnect the spark plug cords from spark plugs (LH Side).
Disconnect the PCV hose from rocker cover (LH).
Remove the bolts, then remove the rocker cover (LH).
Set #1 cylinder piston to top dead center of compression stroke by rotating the crank pulley clockwise using the socket wrench.
Note. When the arrow mark (A) on cam sprocket (LH) comes exactly to the top, #1 cylinder piston is brought to the top dead center of compression stroke.
Scheme 33
Measure #1 cylinder valve clearance using thickness gauge.
| IMPORTANT | Insert the thickness gauge (A) in as horizontally as possible with respect to the valve stem end face. Measure the exhaust valve clearances while lifting-up the vehicle. |
Valve clearance (Standard)
Intake
0.20+/-0.04 mm (0.0079+/-0.0016 in)
Exhaust
0.25+/-0.04 mm (0.0098+/-0.0016 in)
Scheme 34
If necessary, adjust the valve clearance.
Measure the valve clearance in #3, #2 and #4 cylinder in the same measurement procedure as #1 cylinder.
Note. Be sure to set the cylinder pistons to their respective top dead centers on compression stroke before measuring valve clearances. By rotating the crank pulley clockwise every 180° from the state that #1 cylinder piston is on the top dead center of compression stroke, #3, #2 and #4 cylinder pistons come to the top dead center of compression stroke in this order.
After inspection, install the related parts in the reverse order of removal.
Check pipes, hoses, connectors and clamps are installed firmly.
Check that the engine coolant and ATF are at specified levels.
Start the engine, and make sure that no leaks of exhaust gas, engine coolant and fuel, noise and vibrations.
Make sure that no crack or other damages do not exist.
Replace the belts, if cracks, fraying or wear is found.
Remove the V-belt cover and reservoir tank. (with belt tension gauge)
Check the V-belt tension and adjust it if necessary by changing the generator installing position or idler pulley installing position.
(A)
When installing new parts
618 - 755 N (63 - 77 kgf, 139 - 170 lb)
At inspection
490 - 640 N (50.0 - 65.3 kgf, 110.2 - 143.9 lb)
(B)
When installing new parts
740 - 880 N (75.5 - 89.7 kgf, 166 - 198 lb)
At inspection
350 - 450 N (35.7 - 45.9 kgf, 78.7 - 101.2 lb)
Scheme 35
(A) Front side belt
(B) Rear side belt
C/P Crank pulley
GEN Generator
P/S Power steering oil pump pulley
A/C Air conditioning compressor pulley
I/P Idler pulley
(A) When installing new parts
7 - 9 mm (0.276 - 0.354 in)
At inspection
9 - 11 mm (0.354 - 0.433 in)
(B)
When installing new parts
7.5 - 8.5 mm (0.295 - 0.335 in)
At inspection
9.0 - 10.0 mm (0.354 - 0.394 in)
Scheme 36
(A) Front side belt
(B) Rear side belt
C/P Crank pulley
GEN Generator
P/S Power steering oil pump pulley
A/C Air conditioning compressor pulley
Make sure the V-belt is not worn or otherwise damaged.
Check the tension of the belt.
Check the cover for damage.
Check the cam sprocket teeth for abnormal wear and scratches.
Make sure there is no free play between cam sprocket and key.
Check the cam sprocket protrusion used for sensor for damage and contamination of foreign matter.
Check the crank sprocket teeth for abnormal wear and scratches.
Make sure there is no free play between crank sprocket and key.
Check the crank sprocket protrusion used for sensor for damage and contamination of foreign matter.
Note. "RANK" shown in the chart refers to the possibility of reason for the trouble in order ("Very often" to "Rarely")
- A - Very often
- B - Sometimes
- C - Rarely
| Symptom | Problem parts, etc. | Possible cause | RANK |
|---|---|---|---|
| 1. Engine does not start. | |||
| 1) Starter does not turn. | Starter | Defective battery-to-starter harness | B |
| Defective starter switch | C | ||
| Defective inhibitor switch | C | ||
| Defective starter | B | ||
| Battery | Poor terminal connection | A | |
| Run-down battery | A | ||
| Defective charging system | B | ||
| Friction | Seizure of crankshaft and connecting rod bearing | C | |
| Seized camshaft | C | ||
| Seized or stuck piston and cylinder | C | ||
| 2) Initial combustion does not occur. | Starter | Defective starter | C |
| Engine control system | A | ||
| Fuel line | Defective fuel pump and relay | A | |
| Lack of or insufficient fuel | B | ||
| Belt | Trouble | B | |
| Defective timing | B | ||
| Compression | Incorrect valve clearance | C | |
| Loosened spark plug or defective gasket | C | ||
| Loosened cylinder head bolt or defective gasket | C | ||
| Improper valve sealing | C | ||
| Defective valve stem | C | ||
| Worn or broken valve spring | B | ||
| Worn or stuck piston rings, cylinder and piston | C | ||
| Incorrect valve timing | B | ||
| Improper engine oil (low viscosity) | B | ||
| 3) Initial combustion occurs. | Engine control system | A | |
| Intake system | Defective intake manifold gasket | B | |
| Defective throttle body gasket | B | ||
| Fuel line | Defective fuel pump and relay | C | |
| Clogged fuel line | C | ||
| Lack of or insufficient fuel | B | ||
| Belt | Trouble | B | |
| Defective timing | B | ||
| Compression | Incorrect valve clearance | C | |
| Loosened spark plug or defective gasket | C | ||
| Loosened cylinder head bolt or defective gasket | C | ||
| Improper valve sealing | C | ||
| Defective valve stem | C | ||
| Worn or broken valve spring | B | ||
| Worn or stuck piston rings, cylinder and piston | C | ||
| Incorrect valve timing | B | ||
| Improper engine oil (low viscosity) | B | ||
| 4) Engine stalls after initial combustion. | Engine control system | A | |
| Intake system | Loosened or cracked intake duct | B | |
| Loosened or cracked PCV hose | C | ||
| Loosened or cracked vacuum hose | C | ||
| Defective intake manifold gasket | B | ||
| Defective throttle body gasket | B | ||
| Dirty air cleaner element | C | ||
| Fuel line | Clogged fuel line | C | |
| Lack of or insufficient fuel | B | ||
| Belt | Trouble | B | |
| Defective timing | B | ||
| Compression | Incorrect valve clearance | C | |
| Loosened spark plug or defective gasket | C | ||
| Loosened cylinder head bolt or defective gasket | C | ||
| Improper valve sealing | C | ||
| Defective valve stem | C | ||
| Worn or broken valve spring | B | ||
| Worn or stuck piston rings, cylinder and piston | C | ||
| Incorrect valve timing | B | ||
| Improper engine oil (low viscosity) | B | ||
| 2. Rough idle and engine stall | Engine control system | A | |
| Intake system | Loosened or cracked intake duct | A | |
| Loosened or cracked PCV hose | A | ||
| Loosened or cracked vacuum hose | A | ||
| Defective intake manifold gasket | B | ||
| Defective throttle body gasket | B | ||
| Defective PCV valve | C | ||
| Loosened oil filler cap | B | ||
| Dirty air cleaner element | C | ||
| Fuel line | Defective fuel pump and relay | C | |
| Clogged fuel line | C | ||
| Lack of or insufficient fuel | B | ||
| Belt | Defective timing | C | |
| Compression | Incorrect valve clearance | B | |
| Loosened spark plug or defective gasket | B | ||
| Loosened cylinder head bolt or defective gasket | B | ||
| Improper valve sealing | B | ||
| Defective valve stem | C | ||
| Worn or broken valve spring | B | ||
| Worn or stuck piston rings, cylinder and piston | B | ||
| Incorrect valve timing | A | ||
| Improper engine oil (low viscosity) | B | ||
| Lubrication system | Incorrect oil pressure | B | |
| Defective rocker cover gasket | C | ||
| Cooling system | Over-heating | C | |
| Other | Evaporative emission control system malfunction | A | |
| Stuck or damaged throttle valve | B | ||
| 3. Low output, hesitation and poor acceleration | Engine control system | A | |
| Intake system | Loosened or cracked intake duct | A | |
| Loosened or cracked PCV hose | A | ||
| Loosened or cracked vacuum hose | B | ||
| Defective intake manifold gasket | B | ||
| Defective throttle body gasket | B | ||
| Defective PCV valve | B | ||
| Loosened oil filler cap | B | ||
| Dirty air cleaner element | A | ||
| Fuel line | Defective fuel pump and relay | B | |
| Clogged fuel line | B | ||
| Lack of or insufficient fuel | C | ||
| Belt | Defective timing | B | |
| Compression | Incorrect valve clearance | B | |
| Loosened spark plug or defective gasket | B | ||
| Loosened cylinder head bolt or defective gasket | B | ||
| Improper valve sealing | B | ||
| Defective valve stem | C | ||
| Worn or broken valve spring | B | ||
| Worn or stuck piston rings, cylinder and piston | C | ||
| Incorrect valve timing | A | ||
| Improper engine oil (low viscosity) | B | ||
| Lubrication system | Incorrect oil pressure | B | |
| Cooling system | Over-heating | C | |
| Over-cooling | C | ||
| Other | Evaporative emission control system malfunction | A | |
| 4. Surging | Engine control system | A | |
| Intake system | Loosened or cracked intake duct | A | |
| Loosened or cracked PCV hose | A | ||
| Loosened or cracked vacuum hose | A | ||
| Defective intake manifold gasket | B | ||
| Defective throttle body gasket | B | ||
| Defective PCV valve | B | ||
| Loosened oil filler cap | B | ||
| Dirty air cleaner element | B | ||
| Fuel line | Defective fuel pump and relay | B | |
| Clogged fuel line | B | ||
| Lack of or insufficient fuel | C | ||
| Belt | Defective timing | B | |
| Compression | Incorrect valve clearance | B | |
| Loosened spark plug or defective gasket | C | ||
| Loosened cylinder head bolt or defective gasket | C | ||
| Improper valve sealing | C | ||
| Defective valve stem | C | ||
| Worn or broken valve spring | C | ||
| Worn or stuck piston rings, cylinder and piston | C | ||
| Incorrect valve timing | A | ||
| Improper engine oil (low viscosity) | B | ||
| Cooling system | Over-heating | B | |
| Other | Evaporative emission control system malfunction | C | |
| 5. Engine does not return to idle. | Engine control system | A | |
| Intake system | Loosened or cracked vacuum hose | A | |
| Other | Stuck or damaged throttle valve | A | |
| 6. Dieseling (Run on) | Engine control system | A | |
| Cooling system | Over-heating | B | |
| Other | Evaporative emission control system malfunction | B | |
| 7. After burning in exhaust system | Engine control system | A | |
| Intake system | Loosened or cracked intake duct | C | |
| Loosened or cracked PCV hose | C | ||
| Loosened or cracked vacuum hose | B | ||
| Defective PCV valve | B | ||
| Loosened oil filler cap | C | ||
| Belt | Defective timing | B | |
| Compression | Incorrect valve clearance | B | |
| Loosened spark plug or defective gasket | C | ||
| Loosened cylinder head bolt or defective gasket | C | ||
| Improper valve sealing | B | ||
| Defective valve stem | C | ||
| Worn or broken valve spring | C | ||
| Worn or stuck piston rings, cylinder and piston | C | ||
| Incorrect valve timing | A | ||
| Lubrication system | Incorrect oil pressure | C | |
| Cooling system | Over-cooling | C | |
| Other | Evaporative emission control system malfunction | C | |
| 8. Knocking | Engine control system | A | |
| Intake system | Loosened oil filler cap | B | |
| Belt | Defective timing | B | |
| Compression | Incorrect valve clearance | C | |
| Incorrect valve timing | B | ||
| Cooling system | Over-heating | A | |
| 9. Excessive engine oil consumption | Intake system | Loosened or cracked PCV hose | A |
| Defective PCV valve | B | ||
| Loosened oil filler cap | C | ||
| Compression | Defective valve stem | A | |
| Worn or stuck piston rings, cylinder and piston | A | ||
| Lubrication system | Loosened oil pump attaching bolts and defective gasket | B | |
| Defective oil filter seal | B | ||
| Defective crankshaft oil seal | B | ||
| Defective rocker cover gasket | B | ||
| Loosened oil drain plug or defective gasket | B | ||
| Loosened oil pan fitting bolts or defective oil pan | B | ||
| 10. Excessive fuel consumption | Engine control system | A | |
| Intake system | Dirty air cleaner element | A | |
| Belt | Defective timing | B | |
| Compression | Incorrect valve clearance | B | |
| Loosened spark plug or defective gasket | C | ||
| Loosened cylinder head bolt or defective gasket | C | ||
| Improper valve sealing | B | ||
| Defective valve stem | C | ||
| Worn or broken valve spring | C | ||
| Worn or stuck piston rings, cylinder and piston | B | ||
| Incorrect valve timing | B | ||
| Lubrication system | Incorrect oil pressure | C | |
| Cooling system | Over-cooling | C | |
DIAGNOSIS PROCEDURE
| Type of sound | Condition | Possible cause |
|---|---|---|
| Regular clicking sound | Sound increases as engine speed increases. | Valve mechanism is defective. Incorrect valve clearance Worn valve rocker Worn camshaft Broken valve spring |
| Heavy and dull clank | Oil pressure is low. | Worn camshaft main bearing Worn connecting rod bearing (big end) |
| Oil pressure is normal. | Damaged engine mounting | |
| High-pitched clank (Spark knock) | Sound is noticeable when accelerating with an overload. | Ignition timing advanced Accumulation of carbon inside combustion chamber Wrong spark plug Improper gasoline |
| Clank when engine speed is 1,000 to 2,000 RPM | Sound is reduced when fuel injector connector of noisy cylinder is disconnected. (NOTE*) | Worn camshaft main bearing Worn bearing at crankshaft end of connecting rod |
| Knocking sound when engine is operating under idling speed and engine is warm | Sound is reduced when fuel injector connector of noisy cylinder is disconnected. (NOTE*) | Worn cylinder liner and piston ring Broken or stuck piston ring Worn piston pin and hole at piston end of connecting rod |
| Sound is not reduced if each fuel injector connector is disconnected in turn. (NOTE*) | Unusually worn valve lifter Worn cam sprocket Worn camshaft journal bore in crankcase | |
| Squeaky sound | Insufficient generator lubrication | |
| Rubbing sound | Defective generator brush and rotor contact | |
| Gear scream when starting engine | Defective ignition starter switch Worn gear and starter pinion | |
| Sound like polishing glass with a dry cloth | Loose drive belt Defective water pump shaft | |
| Hissing sound | Loss of compression Air leakage in air intake system, hoses, connections or manifolds | |
| Timing belt noise | Loose timing belt Belt contacting with case/adjacent part | |
| Valve tappet noise | Incorrect valve clearance |
DIAGNOSIS PROCEDURE