IGNITION SYSTEM - Service Adjustment Procedures 8-111
SERVICE ADJUSTMENT PROCEDURES
CHECKING IGNITION TIMING NOEGIBA
IGNITION TIMING ADJUSTMENT
Adjustment conditions:
Coolant temperature: 80-90°C (170-I 90°F)
Lights and all accessories: Off
Transmission: N (Neutral)
1. Connect tachometer and timing light.
2. Start eng.ine and run at curb idle speed.
I
Curb idle speed rpm
First 500 km
(300 mile)
After 500 km
(300 mile)
725';;;
800 ?I00 3. To make adjustment at high altitude, disconnect pressure
sensor connector before stopping engine. Then restart
engine and run it at curb idle speed.
4. Check basic ignition timing and adjust if necessary.
Basic ignition timing: 7” + 2”BTDC 5. To adjust ignition timing, loosen distributor mounting nut
and turn distributor housing.
6. After adjustment, securely tighten mounting nut.
7. Reconnect pressure sensor connector disconnected in
Step 3. Then run engine at curb idle speed to make sure
that actual ignition timing is obtained.
. .
CHECKING IGNITION SYSTEM NOBDIDB
CHECKING CENTRIFUGAL ADVANCE EQUIPMENT 1.
Set the tachometer and timing light.
2. Start the engine and allow it to idle.
3. Pull out vacuum hose from vacuum controller.
4. Check the advance while slowly raising RPM. If the advance is
smooth when accompanying the increasing RPM, this is
normal.
Symptom Assumed causes
Excessive advance
Weakness of the governor spring
Sudden advance rise
Broken spring
Insufficient advance or large
Impaired movement of the gover-
hysteresis
nor weight or cam.
5. If the malfunction indicators above are confirmed, dismantle
and check the distributor.
6. After checking, let the engine idle and then turn the ignition
switch to OFF.
7. Remove the tachometer and timing light.‘.
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AIR-CONDITIONING -Service Adjustment Procedures 24-41
COMPRESSOR NOISE NWLM
When investigating an air conditioning related noise, you must first know the conditions when the noise occurs.
These conditions are: weather, vehicle speed, in gear or neutral, engine temperature or any other special
conditions.
Noises that develop during air- conditioning operation can often be misleading. For example: what sounds like a
failed front bearing or connecting rod, may be caused by loose bolts, nuts, mounting brackets, or a loose clutch
assembly. Verify accessory drive belt tension (power
steering, alternator or air pump). Improper accessory drive belt
tension can cause a misleading noise when the compressor is engaged and little or no noise when the compressor
is disengaged.
Drive belts are speed sensitive. That is, at different engine speeds, and depending upon belt tension, belts can
develop unusual noises that are often mistaken for mechanical problems within the compressor.
Adjustment Procedures
(1) Select a quiet area for testing. Duplicate conditions as much as possible. Switch compressor on and off several
times to clearly identify compressor noise.
To duplicate high ambient conditions (high head pressure), restrict air-flow through
condenser. Install
manifold gauge set to make sure discharge pressure does not exceed 2,070 kPa (300 psi).
(2) Tighten all compressor mounting bolts, clutch mounting bolt, and compressor drive belt. Check to assure clutch
coil is tight (no rotation or wobble).
(3) Check refrigerant hoses for rubbing or interference that can cause unusual noises.
(4) Check refrigerant charge (See “Charging the System”).
(5) Recheck compressor noise as in Step 1.
(6) If noise still exists, loosen compressor mounting bolts and retorque. Repeat Step 1.
(7) If noise continues, replace compressor and repeat Step 1.
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