TM10-3930-660-20 Table 2-3. Mechanical Troubleshooting (Cont’d) MALFUNCTION TEST OR INSPECTION CORRECTIVE  ACTION b. Remove and clean tail pipe. Step 4. Step 5. 3. ENGINE Step 1. Check for plugged  fuel  filter. Drain water separator or replace fuel filter head, TM10-3930-660-10 and para. 5-16. Check for lack of fuel at injection pump or aerated fuel. Check for fuel flow and bleed fuel system, para. 5-12. HARD TO START OR WILL NOT START - SMOKE FROM EXHAUST Check for cranking speed too slow. a. b. Check for low battery output with STE/ICE. Battery voltage should be 24 volts or higher. Service or replace batteries as required if voltage is below 24 volts.   Refer to TM9-6140-200-14. Check starting system. Refer to Starting System section of Electrical Troubleshooting Table  2-2. Repair and/or replace starting system components and wiring as necessary. 2-26