ARMY TM 9-2815-260-24 AIR FORCE TO 38G1-126-2 MARINE CORPS TM 09244A/09245A-24 4-10 TABLE 4-1.  DIRECT SUPPORT TROUBLESHOOTING (Sheet 9 of 12) Not OK   OK   Not OK   Not OK   OK   Not OK   OK   BLACK OR GRAY EXHAUST SMOKE Black or gray exhaust smoke. Check for dirty, defective, or leaking  fuel injection nozzles (refer to paragraph 3.12.6). Clean, repair, or replace fuel injection nozzles (refer to paragraph 4.6.2). Test fuel injection pump timing (refer to paragraph 5.3.1). Time fuel injection pump (refer to paragraph 5.3.1). Check for defective turbocharger (refer to paragraph 4.4.1). Perform end item troubleshooting procedures (refer to TM 9-6115-672-14 or other applicable TM). Check for defective fuel injection pump (refer to paragraph 5.3.1). Replace fuel injection pump (refer to paragraph 5.3.1). Replace turbocharger (refer to paragraph 4.4.1). Notify next higher level of maintenance. OK