ARMY TM 9-2815-254-24 AIR FORCE TO 38G1-94-2 Table  3-2.  Troubleshooting  -  Continued MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION Step  5. Step  6. Step  7. Defective fuel injection pump. a. Remove and test fuel injection pump. Refer to paragraph 3-11.5. If fuel injection pump not defective, go to step 6. b. Replace fuel injection pump. Refer to paragraph 3-11. Check for low engine compression. a. Perform engine compression check. Refer to paragraph 3-27.7. If compression good, do step 7. b. If engine defective, repair or replace engine. Check for valves improperly adjusted. Adjust valves. Refer to paragraph 3-26.6. BLACK OR GRAY SMOKE. Step 1. Step 2. Step  3. Step  4. Check for blocked air intake system. Remove blockage as found. lf no blockage is found, do step 2. Check for defective fuel injectors. a. Test fuel injectors. Refer to paragraph 3-10. If not defective, do step 3. b. Replace fuel injectors. Refer to paragraph 3-10. Check for improper fuel injection pump timing. a. Check  fuel  injection  pump  timing.  Refer  to  paragraph  3-13.1.  If  fuel  injection  timing  is  correct, do step 4. b. Adjust fuel injection pump timing. Refer to paragraph 3-13.2. Defective fuel injection pump. a. Remove and test fuel injection pump. Refer to paragraphs 3-11.5. b. Repair or replace fuel injection pump. Refer to paragraph 3-11. 12. BLUE  EXHAUST  SMOKE. Step 1. Check for blocked air intake system. Remove blockage as found. lf no blockage is found, do step 2. Step 2. Check for defective intake or exhaust valve seals or valve guides. a. Repair or replace defective components. Refer to paragraph 3-27.4. b. Disassemble  and  inspect  valve  seals  and  guides.  Refer  to  paragraph  3-27.2.  lf  not  defective, replace engine. 3-8