TM 9-6115-670-14&P 5-5 2.  ENGINE TURNS OVER BUT FAILS TO START. STEP 1. Check to see if proper starting procedures were followed. a.  If proper starting procedures were not followed, start APU per para. 2-5. b.  If proper starting procedures were followed, proceed to step 2. STEP 2. Check for low or no vehicle fuel supply. a.  If vehicle fuel tank is low, service vehicle fuel tank. b.  If vehicle fuel tank has adequate amount of fuel, proceed to step 3. STEP 3. Check for closed Selector valve on fuel filter. a.  If fuel selector valve is closed, open fuel selector valve. b.  If fuel selector valve is open, proceed to step 4. STEP 4. Check for defective injection timing. a.  If injection timing is not correct, ADJUST timing (para. 5.14.). b.  If injection timing is correct, proceed to step 5. STEP 5. Check for defective injection pump. a.  If injection pump is defective, REPLACE pump (para. 5.14.). b.  If injection pump is functioning properly, proceed to step 6. STEP 6. Check for defective injection nozzle holder assembly. a.  If  injection  nozzle(s)  clogged,  clean  nozzle(s).    If  nozzle  holder  assembly  is defective, REPLACE holder assembly (para. 5.13.). b. If nozzle holder assembly is functioning properly and injection nozzle(s) unclogged, proceed to step 7. STEP 7.  Check for excessive valve clearance. a.   If value clearance exceeds tolerance, ADJUST clearance (para. 5.29.). b.  If value clearance meets tolerance, notify next higher level of maintenance.