TM  9-2815-202-34 2-5. MALFUNCTION,  TEST  OR  INSPECTION,  AND  CORRECTIVE  ACTION PROCEDURES   (Cont) MALFUNCTION TEST OR INSPECTION CORRECTIVE  ACTION ABNORMAL  ENGINE  OPERATION 4. UNEVEN  RUNNING  OR  STALLING Step  1.  Check  fuel  supply  level. Step 2. Check fuel strainer and fuel filter for Ieaking gaskets, clogged filters, or loose connections. Step 3. Check fuel lines for loose connections, damage, twists, and bends. Step 4. Check fuel spill back for air in fuel system. a. Disconnect fuel return line from fitting at fuel tank. Hold end of fuel line in a container. WARNING Protective fan screens must be installed prior to doing maintenance  in  the  engine  compartment  when  engine is running or when engine is in ground hop mode. Contact  with  rotating  fan  can  cause  injury  (reference FM   21-11). b.  Start  engine  and  run  at  1200  RPM. NOTE Air bubbles rising to surface indicate air being drawn into fuel system. c. Measure fuel; 0.8 GPM is required. Step 5. Check engine tune up adjustments (Refer to Para 8-5). WARNING Protective fan screens must be installed prior to doing maintenance  in  the  engine  compartment  when  engine is running or when engine is in ground hop mode. Contact  with  rotating  fan  can  cause  injury  (reference FM   21-11). Step 6. Check  for  faulty  injectors. a.  Remove  rocker  arm  cover. b.  Start  engine. 2-6