Chevrolet 70 Series 1970, Service Manual

Page: 453 / 841

53 AND 71 SERIES DIESEL ENGINES 6C-56
HARD STARTING—Cont.
FUEL—Cont.
INJECTOR RACKS NOT IN FULL FUEL POSITION-Check control tube for binds and reset
governor and control rack, if necessary.
FUEL TANK OR FUEL FILTER EMPTY—Fill fuel tank or prime filter.
IMPROPER GRADE AND TYPE FUEL-Refer to Current Diesel Fuel Oil Service Bulletin.
DILUTED FUEL—Check storage and handling methods.
IMPROPERLY FILTERED OR RESTRICTED FUEL FLOW-Refer to “No Fuel or Insufficient
Fuel”
AIR IN FUEL SYSTEM -Bleed air from fuel system at secondary fuel filter.
ABNORMAL ENGINE OPERATION
UNEVEN RUNNING OR FREQUENT STALLING
CYLINDERS CUTTING OUT-Check for the following:
1. Valve Clearance Set Incorrectly—Readjust valve clearance as directed under “Valve Lash”
in “Engine Tune-up” section.
2. Insufficient Fuel—Refer to “No Fuel or Insufficient Fuel”.
3. Faulty Injector—Refer to “Injector Tests” under “Fuel Injectors” in “Fuel System”
(SECTION 6 C ).
COOLING SYSTEM TEMPERATURE BELOW NORMAL-Refer to “Abnormal Engine Coolant
Temperatures”.
NO FUEL OR INSUFFICIENT FUEL-Refer to “No Fuel or Insufficient Fuel”.
FAULTY INJECTORS—
1. Improper Timing of Injectors—Retime injectors as directed under “Injector Timing”
in (Section 6C ),
2. Incorrect Rack Setting—Readjust injector racks as outlined in (Section 6C ).
3. Injector Spray Tip Leaks—Replace fuel injector.
CYLINDER PRESSURES LOW-Refer to “Hard Starting”.
GOVERNOR INSTABILITY (HUNTING)-Check for the following:
1. Governor Instability—Perform engine tune-up.
2. Binding Injector Rack—Replace injector.
3. Faulty Adjustments—Perform tune-up operations in sequence as instructed in “Engine
Tune-up” section.
IMPROPER GRADE AND TYPE FUEL-Refer to Current Diesel Fuel Oil Service Bulletin.
DILUTED FUEL—Check storage and handling methods.
IMPROPERLY FILTERED OR RESTRICTED FUEL FLOW-Refer to “No Fuel or Insufficient
Fuel” T-6932
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL