ARMY TM 9-2815-253-24
AIR FORCE TO 38G1-93-2
MARINE CORPS TM 2815-24/3
Table 3-2. Troubleshooting Continued
TEST OR INSPECTION
Step 5. Check for improper fuel pump timing.
a. If timing is correct, do Step 6.
b. Adjust fuel pump timing. R refer to paragraph 3-14.
Step 6. Defective fuel injection pumps.
a. Test fuel injection pumps. Refer to paragraph 3-13.3.
b. Replace fuel injection pump(s). Refer to paragraph 3-13.
11. BLACK OR GRAY SMOKE.
Step 1. Check for defective fuel injectors.
a. Remove and test fuel injectors. Refer to paragraph 3-17. If not defective, do Step 2.
b. Replace fuel injector(s). Refer to paragraph 3-17.
Step 2. Check for improper fuel pump timing.
a. Adjust fuel pump timing. Refer to paragraph 3-14.
b. If fuel pump timing is OK. Repair or replace engine.
12. BLUE EXHAUST SMOKE.
Step 1. Check for blocked air intake system.
Remove blockage as found. If no blockage is found, do Step 2.
Step 2. Check for loss in vacuum.
a. Perform vacuum check. Refer to paragraph 3-5.2.
b. If vacuum is correct, proceed with Step 3.
c. If vacuum is not good, repair or replace engine.
Step 3. Check for defective intake or exhaust valve seals or valve guides.
a. Repair or replace defective components. Refer to paragraph 3-27.
b. Disassemble and inspect valve seals and guides. Refer to paragraph 3-27. If not defective, repair or