1993 Geo Metro Base, 2D Hatchback, AutomaticFACTORY OEM SERVICE PROCEDURE

Ignition Timing

IGNITION TIMING SPECIFICATIONS (Degrees BTDC @ RPM) (1)

Application Man. Trans. Auto. Trans.
Metro (2) 5 @ 750-850 (2) 5 @ 800-900
(1) If specification differs from emission label, use specification listed on emission label.
(2) With jumper wire installed between terminals "D" (Black wire) and "E" (Purple/Green wire) of duty check data link connector, located on left strut tower.
  1. Start engine, and warm it to normal operating temperature. Turn engine off but keep ignition on for 5 seconds. Restart engine, and raise engine speed to 2000 RPM for 5 minutes. Return to idle. Ensure all accessories are off and idle speed is within specification. Adjust idle speed first if it is not within specification. See IDLE SPEED  under IDLE SPEED & MIXTURE.
  2. Connect timing light to No. 1 spark plug wire. Remove cap from duty check Data Link Connector (DLC), located in rear corner of engine compartment near left strut tower. Connect a jumper wire between terminals "D" (Black wire) and "E" (Purple/Green wire) of duty check DLC. See Fig 1 .
  3. Check timing mark alignment on crankshaft pulley with timing marks on timing belt cover. Ignition timing must be within specification. See IGNITION TIMING SPECIFICATIONS  table.
  4. If ignition timing is not as specified, loosen distributor hold-down flange bolts, and rotate distributor to obtain correct ignition timing. Tighten distributor hold-down flange bolts to 11 ft. lbs. (15 N.m). Recheck ignition timing.
  5. Turn engine off. Remove jumper wire, and install cap on duty check DLC. Remove test equipment.
Fig 1: Duty Check DLC Terminal ID
G93G78085Courtesy of GENERAL MOTORS CORP.
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