DIAGNOSTIC ANALYSIS Section 2 • If turbocharged, inspect compressor housing for signs of oil leakage. • Inspect the cooling system, overcooling can sometimes cause blue smoke. • Check the "AIR INDUCTION SYSTEM." b. GRAY  SMOKE  depending  on  the  specific level, can be caused by the injection nozzle condition and/or air induction system.  Gray smoke will exceed specified levels: • If air cleaner restriction is high or • If injection system does not meet "PERFORMANCE DATA GUIDELINE" specifications. Remove and test nozzles. c. BLACK    SMOKE    must    be    immediately corrected.          All     areas     of     appropriate "PROBLEM   ANALYSIS   GUIDE"   (CGES- 390,      365,   335-2,   or   355-3)   must   be investigated to determine cause. • If    problem   cannot   be   resolved   by   analysis, remove   injection   pump   for   a   test   stand analysis. d. WHITE SMOKE - generally indicates • Excess fuel on starting with • Insufficient cranking speed or • Defective nozzles. These  conditions  result  in  misfiring  with  warm engine. 5. In  general,  any  excess  smoke  problem  can  be resolved   by   following   the   procedures   in   the appropriate "PERFORMANCE ANALYSIS GUIDE". EVALUATING NORMAL EXHAUST SMOKE (6.9 Liter Diesel only) BLUE-WHITE SMOKE CAN BE OBSERVED •· At engine start up at all engine temperatures and at all ambient temperatures. •· At low idle speeds after cold engine start up this smoke  will  clear  up  soon  after  the  vehicle  is driven. • After the engine warm up period due to extended idling time (ten minutes or more). DARKER SMOKE CAN BE OBSERVED • When  pulling  hard,  such  as  going  up  a  steep grade. • Heavily   loaded,   such   as   pulling   a   trailer   or operating with a heavy load in the truck bed. • During acceleration. NOTE: Black  smoke  under  the  above conditions will be much more pronounced at higher altitudes. High altitude fuel adjustment instructions  are  available  through  IH dealers   in   those   areas,   as   well   as CGES-345   6.9L   Fuel   Injection   Pump Service Manual. VERY IMPORTANT: DO NOT OPERATE    ENGINE    ABOVE    RATED SPEED. Operating above rated speed at no load high idle or light load conditions will result in: • WHITE - BLUE/WHITE SMOKE. • GOVERNOR HUNTING - SURGE. • SPUTTERING OR MISFIRE. These conditions occur because at W.O.T. the face cam is in the full retard position and the min-max.  governor is cutting fuel delivery back to idle quantities, which causes: • SPEED   VARIATION   AND   VERY   RETARDED VARIABLE TIMING. .  .  .  LOW POWER 1. Verify problem: a. Determine   how   power   or   performance   is checked. b. Compare   to   identical   units   in   same   type operation.(Refer to "PERFORMANCE DATA  GUIDELINES"  in  the  rear  of  each Engine Section). 2. Determine cause of problem: a. Check   fuel   type   and   grade.      Refer   to appropriate "OPERATION AND MAINTENANCE" manual. CGES-240-4 Printed in United States of America Page 3