TM-9-2320-280-34

TRUCK, UTILITY: M998 SERIES

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE

JANUARY 1996
TM-9-2320-280-34

  TM-9-2320-280-34 - Page 30 of 1258

TM 9-2320-280-34
2 - 6
Change 1
MALFUNCTION
TEST OR INSPECTION
Table 2-1. Mechanical Troubleshooting (Cont'd)
8.
EXCESSIVE EXHAUST SMOKE
a. Black Smoke
Step 1.
Check for restricted exhaust pipe and intake manifold. Replace exhaust pipes (TM 9-2320-280-20) or
intake manifold (para. 3-17) if restricted.
Step 2.
Remove and test fuel injection nozzles (para. 4-3). Replace defective fuel injection nozzles.
Step 3.
Check fuel injection pump timing (para. 3-20).
Step 4.
Check for defective fuel injection pump (TM 9-2815-237-34). Replace defective fuel injection pump (para. 4-6).
END OF TESTING!
b. White Smoke
Step 1.
Perform step 2 of malfunction 12.
Step 2.
Remove and test glow plugs (TM 9-2815-237-34). Replace defective glow plugs.
Step 3.
Remove and test fuel injection nozzles (para. 4-3). Replace defective fuel injection nozzles.
Step 4.
Check for defective fuel injection pump (TM 9-2815-237-34). Replace defective fuel injection pump (para. 4-6).
END OF TESTING!
c. Blue Smoke
Step 1.
Perform step 3 of malfunction 2.
Step 2.
Check for defective valve seals. Replace defective valve seals (TM 9-2815-237-34).
Step 3.
Check for worn valve guides. Repair worn valve guides (TM 9-2815-237-34).
Step 4.
Check for worn or damaged pistons and piston rings. Replace worn or damaged pistons and piston rings
(TM 9-2815-237-34).
Step 5.
Check for worn or damaged cylinder block. Replace engine (para. 3-22 or 3-24) if cylinder block is worn or
damaged.
END OF TESTING!
9.
ACCELERATOR PEDAL STICKS OR FULL THROTTLE CANNOT BE OBTAINED
Step 1.
Disconnect modulator cable from modulator link. Pull cable in and out to check for free operation. If
modulator cable binds, replace modulator cable (TM 9-2320-280-20).
Step 2.
Disconnect accelerator cable from fuel injection pump. Move throttle lever on injection pump to wide open
throttle. If throttle lever does not move freely, replace injection pump (para. 4-6).
END OF TESTING!
10. LEAKING EXHAUST GASES OR EXHAUST NOISES
Check for leaking exhaust gases around exhaust manifolds. Replace any leaking exhaust manifold gaskets or
exhaust manifolds (TM 9-2320-280-20).
END OF TESTING!


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