LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 1985 >> Spectrum 2D Hatchback, Automatic >> Repair and Diagnosis >> Engine Performance >> Adjustment >> Tune-Up - 4-CYL >> Adjustments >> Ignition Timing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Ignition Timing

  1. Engine must be at operating temperature. Connect tachometer and timing light to engine. Check timing with transmission in Neutral, all vacuum hoses connected, and all accessories turned off.
  2. Adjust idle speed to specifications. Adjust timing by loosening lock nut and turning distributor. Tighten lock nut and recheck timing.
IGNITION TIMING SPECIFICATIONS (DEGREES BTDC @ RPM)

Man. Trans. Auto. Trans.
15° @ 750 10° @ 1000