LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Hummer >> 2006 >> H3 Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 3.5L - Trouble Shooting >> Hard Start
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Hard Start

Hard Start

Inspection/Test Action
DEFINITION: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies.
Preliminary
Sensor/System
Fuel System
Ignition System
  • In order to properly inspect the spark plugs or to correct a condition, refer to the following procedures:
  • Remove spark plugs and inspect for the following:
    • Correct heat range
    • Wet plugs
    • Cracks
    • Wear
    • Improper gap
    • Burned electrodes
    • Heavy deposits
    • Spark plugs are of the correct type.
  • Inspect for proper secondary ignition voltage output with J 26792  HEI Spark Tester. See Special Tools .
  • An improper spark plug gap will cause a driveability condition. Gap the spark plugs using a wire gauge gap tool.
  • If the spark plugs are found to be fouled, determine the cause before replacing the spark plugs.
  • Inspect for damaged or misaligned spark plug boots.
Engine Mechanical Inspect for the following conditions:
Additional
  • Inspect for a restricted exhaust. Refer to Restricted Exhaust in Engine Exhaust.
  • Inspect the air intake ducts for being collapsed, damaged, loose, improperly installed, or leaking.