TM 9-2320-260-34-1
Table 2-1. Mechanical Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE
WARNIN6
Ensure fuel shutoff valve is off and remove throttle cable before
cranking engine. Failure to do so may result in injury to personnel.
Step 1. Hand rotate engine at crankshaft two complete turns.
Proceed to step 2 if engine does not turn.
Step 2. Remove rocker lever housings (para. 3-15) and remove decompression plugs. Rotate engine.
a. If engine rotates and ejects liquid, determine if liquid is coolant or fuel. Install rocker
lever housing (para. 3-15).
(1) Proceed to step 3 if liquid is coolant.
(2) Proceed to step 4 if liquid is fuel.
b. Proceed to step 5 if engine does not rotate.
Step 3. Check for coolant liquid lock.
a. Perform coolant system pressure test to confirm coolant leak into combustion space
b. Remove and inspect cylinder heads (para. 3-18). Replace cylinder head(s) if cracked or
warped.
c. Repeat coolant system pressure test. Cylinder liner or block is cracked if coolant leak is
still present. Replace engine (para. 3-24).
Step 4. Check for fuel liquid lock.
a. Shut off fuel at fuel inlet to fuel pump (TM 9-2320-260-10).
b. Remove rocker lever housing covers (para. 3-14), turn engine, and observe for proper
injector arm movement.
(1) Replace fuel injector(s) (para. 5-6) if injector arm movement is correct.
(2) Remove cam follower housing (para. 3-19), rotate engine, and check cams and
mechanical linkage to injectors if injector arm movement is not correct. Install cam
follower housing (para. 3-19).
Step 5. Check for mechanical lockup.
a. Remove fuel pump (para. 5-13).
(1) Replace fuel pump if engine rotates.
(2) Proceed to b. if engine does not rotate.
b. Remove air compressor (para. 11-3).
(1) Replace air compressor if engine rotates.
(2) Proceed to c. if engine does not rotate.
c. Remove accessory drive (para. 3-9).
(1) Replace accessory drive if engine rotates.
(2) Replace engine if engine still does not rotate (para. 3-24).
END OF TESTING!
