Chevrolet 70 1969 Series, Shop Manual

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6V-53 DIESEL ENGINE 6C-13
A B N O R M A L ENG INE O PERATION-Cont.
DETONATION
OIL PICKED UP BY AIR STREAM-Check for the following:
1. Oil Pull Over From Air Cleaners—Remove, clean, and fill air cleaners with engine oil to
proper oil level.
2. Accumulation in Air Box—Clean air box and air box drain tubes.
3. Defective Blower to Cylinder Block Gasket—Remove blower and gasket and install a new
gasket and reinstall blower.
4. Leaking Blower Oil Seals—Remove and overhaul blower.
LOW COOLANT TEMPERATURE—Refer to “Abnormal Engine Coolant Temperatures” chart.
FAULTY INJECTORS-Check for the following:
1. Improper Timing—Retime injectors as directed under “Injector Timing” in
(Section 6M).
2. Check Valve Leaking—Replace injector.
3. Spray Tip Holes Enlarged—Replace injector.
4. Broken Spray Tip—Replace injector.
LACK OF POWER
IMPROPER ENGINE ADJUSTMENTS-Check for the following:
1. Governor Gap Set Incorrect—Perform tune-up operations as directed in
(Section 6M ).
2. Rack Setting Incorrect—Perform tune-up operations as directed in
(Section 6M ).
3. Injector Timing Incorrect—Time fuel injectors as directed under “Injector Timing” in
(Section 6M ).
4. Valve Clearance Set Incorrectly—Readjust valve clearance as directed under “Valve Lash”
in “Engine Tune-up” section.
INSUFFICIENT FUEL-Refer to “No Fuel or Insufficient Fuel” chart.
INSUFFICIENT AIR-Check for the following:
1. Air Cleaners Damaged or Clogged—Remove and clean, repair or replace damaged parts.
2. Cylinder Liner Air Inlet Ports Clogged—Clean cylinder liner ports.
3. Low Compression—Refer to “Low Compression” in “Hard Starting” chart.
4. Blower Air Intake Obstructed—Check and clean air cleaner and air inlet horn and screen.
5. Excessive Exhaust Back Pressure—Inspect exhaust pipe and muffler and replace if
damaged.
CHEVROLET SERIES 70 -80 H EAVY DUTY TRUCK SH OP M A N U A L