TM   10-3930-643-20 PRELIMINARY   PROCEDURES.   (cont) 3-6. Troubleshooting    Symptom    Index. The   following   contains   an   index   of   all   troubleshooting   data   located   within   the manual. Included   in   the   index   are   the   paragraph/malfunction   and   page   where   the detailed   procedure   will   be   found. GENERAL  INFORMATION. This  list  of  MALFUNCTIONS  will  give  you  an  indication  of where   a   possible   problem   might   be   found. MALFUNCTION  IDENTIFICATION  PROCEDURES. To   use   this   symptom   index   effectively, follow   this   procedure: FIRST  : SECOND : THIRD : Locate   the   appropriate   MALFUNCTION   from   this   index   and   go   to   the troubleshooting    procedure paragraph designated..    locate the MALFUNCTION. Do   the   TEST   OR   INSPECTION   until   you   verify   where   the   problem o r i g i n a t e s. Do   the   CORRECTIVE   ACTION   procedure   to   correct   your   problem. MALFUNCTION TEST OR INSPECTION CORRECTIVE   ACTION Paragraph/ Component/System Malfunction Page ENGINE Engine   hard   to   start   or   will   not   start 4-1a 4-2 Engine   has   sudden   changes   in   speed 4-1b 4-2 Vibration 4-1c 4- 3 Noise-combustion 4-1d 4-3 Noise-mechanical 4-1e 4 -3 Low   oil   pressure 4 - 1 f 4-4 ENGINE  STE/ICE  TESTS Test   10   -   Engine  RPM  (S/N  2001  and  above  only) Test   12   -   Engine   Power   (S/N   2001   and   above   only) Test   14   -   Compression   Unbalance Test   35   -   Engine   Oil   Pressure 4-2a 4-6 4-2b 4-7 4-2c 4-8 4-2d 4-9 3-14