TRUCK SERVICE MANUAL
Correction
Cause
Replace fractured pulsation damper diaphragm.
Check 1: Low fuel manifold pressure.
Replace Idle Plunger (Button) with correct plunger if
Check 2: Fuel manifold pressure too high or too low
incorrect plunger was used. Polish surface of plunger if
because of incorrect Idle Plunger (Button) or surface finish.
rough, burrs or chipped areas are found on surface of
plunger.
Check 3: Gear Pump fails to obtain delivery and pressure.
Replace gear pump.
Check 4: Wrong throttle restriction.
Set throttle restriction to correct values.
Check 5: Test Stand set at wrong flow rate.
Set test stand at flow rate indicated in calibration data
pertinent to fuel pump being calibrated.
Check 6: Throttle screw out of adjustment.
Adjust throttle screw.
Check 7: Governor Weight Carrier assembly incorrect or
faulty.
Replace with correct new governor weight carrier assembly.
Check 8: Scored governor plunger.
Replace with new governor plunger and lap to fit.
Cause
Correction
Polish surface with oil stone or replace if necessary.
Check 1: Idle plunger or governor plunger rough or
voids.
Check 800 RPM checkpoint under Complaint No. 7 to be sure
It is within specifications before proceeding.
Check 2: 800 RPM Checkpoint.
Remove front cover and check for proper torque or
Check 3: Incorrect torque or governor spring.
governor spring and free length of spring. Shim torque
spring.
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