TM 10-3930-669-20 5.  EXCESSIVE SMOKE (CONT). KNOWN INFO TEST OPTIONS Fuel filter OK. Air filter OK. Air intake system not leaking. Fuel connections not leaking. Fuel injectors OK. Air intake not obstructed Fuel injector pump OK. Verify repair. POSSIBLE PROBLEMS REASON FOR QUESTION If engine does not produce excessive  black  or  gray  smoke, fault has been corrected. ¬ 2-80