User Manual

Page 9-2
200 TROUBLESHOOTING
ENGINE WILL NOT CRANK
200766a
ENGINE CRANKS — WILL NOT START
200767a
Possible Cause Correction
1. Batteries have low output. 1. Check the batteries. Charge or replace as required.
2. Loose or corroded battery connections. 2. Clean and tighten battery connections.
3. Broken or corroded wires. 3. Check voltage at the following connections:
— Switch to starter
— Battery to starter
Replace as required.
4. Faulty starter or starter solenoid. 4. Check operation of starter and solenoid. Repair as required.
5. Faulty key switch. 5. Replace key switch.
6. Internal seizure. 6. Bar the engine over one complete revolution. If the engine cannot
be turned, internal damage to the clutch is indicated. Disassemble
clutch or engine and repair as required.
Possible Cause Correction
1. Slow cranking speed. 1. Check corrections listed in preceding section, ENGINE WILL NOT
CRANK.
2. Emergency shut-off valve closed or partially
closed.
2. Check emergency shut-off system. Make necessary repairs.
3. No fuel to engine. 3. Check for fuel in the fuel tank. Also check for plugged fuel tank
connections, restricted or kinked fuel suction lines, fuel transfer
pump failure, or clogged fuel filters.
4. Governor throttle shaft linkage binding/improper
setting of accelerator linkage.
4. Check throttle shaft and accelerator linkage. Repair as necessary.
5. Defective fuel transfer pump. 5. Check transfer pump for minimum output pressure. Change fuel
filters if low. Look for air leaks and recheck pressure. If still below
minimum, replace transfer pump.
6. Poor quality fuel or water in fuel. 6. Drain fuel from tank. Replace fuel filters and fill fuel tank with
MACK-specified diesel fuel.
7. Incorrect engine oil viscosity. 7. Drain oil. Replace oil filters and fill crankcase with recommended
grade oil.
8. Low compression. 8. Check cylinder compression. If low, refer to LOW COMPRESSION
in this section.
9. Injection pump-to-engine timing incorrect. 9. Check injection pump-to-engine timing. Setting is protected by
seals, and must be checked by an authorized MACK Fuel Injection
System Repair facility.
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