Chevrolet 70 1969 Series, Руководство по ремонту

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6V-53 DIESEL ENGINE 6 C -1 1
TROUBLE DIAGNOSIS CHART
The satisfactory performance of a Diesel en­
gine depends on two items of foremost impor­
tance, (1) Sufficiently high compression pressure,
and (2) The injection of the proper amount of
fuel at the right time.
The first one of these items depends entirely
on pistons, piston rings, valves, and valve operat­
ing mechanism; the second item depends on in­
jectors and their operating mechanism, and fuel
system.
Lack of engine power, uneven running, exces­
sive vibration, and tendency to stall when idling
may be caused by either a compression loss or
faulty injector operation.
The causes of trouble symptoms may be
varied; therefore a hit-and-miss search should
be avoided. A proper diagnosis of symptoms is an
orderly process of diagnosing the symptoms. An
“orderly process” means to check the most proba­
ble common cause first; then proceed with the
next probable cause.
The quick reference Trouble Shooting Charts
on pages following list symptoms, with probable
causes, and remedies. References are made to
other charts, also to various sections in this man­
ual, which list correct remedies and procedures.
H ARD STARTING
LOW STARTING R.P.M.
IMPROPER LUBE OIL VISCOSITY-Refer to “Engine Oil Viscosity Chart” in “Lubrication
System” (SECTION O).
INFREQUENT OIL CHANGES—Change oil at recommended intervals.
LOW BATTERY OUTPUT-Check for the following:
1. Poor or Shorted Connections—Properly connect or replace leads and terminals.
2. Undercharged or Defective—Recharge or. replace battery.
3. Low Ambient Temperature—Use a starting aid.
FAULTY STARTER OR LOOSE STARTER CONNECTIONS-Replace starter or tighten con­
nections.
LOW COM PRESSION
EXHAUST VALVES STICKING OR BURNED—Overhaul cylinder head.
COMPRESSION RINGS WORN OR BROKEN-Overhaul cylinder liner assemblies.
CYLINDER HEAD GASKET LEAKING—Replace cylinder head gasket.
IMPROPER VALVE CLEARANCE ADJUSTMENT-Adjust valve clearance.
BLOWER NOT FUNCTIONING—Check blower drive shaft and couplings.
EMERGENCY SHUT-OFF VALVE PARTIALLY OR COMPLETELY CLOSED-Reset.
FUEL
AIR LEAKS, FLOW OBSTRUCTION, FUEL PUMP-Refer to “No Fuel or Insufficient Fuel”
chart.
CHEVROLET SERIES 70 -80 H EAVY DUTY TRUCK SH O P M AN U AL