Difficult To Start: Ascender

The engine cranks normally, but does not start in a normal amount of time. The engine does eventually run, or may start but immediately dies.

• See PRELIMINARY CHECK  .
• Search for bulletins.
• Measure vehicle operator is using the correct starting procedure.
• Monitor the Engine Coolant Temperature (ECT) sensor with the scan tool. Compare the engine coolant temperature with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5 degrees more or less than the ambient air temperature on a cold engine, check for high resistance in the coolant sensor circuit.
• Inspect for a restricted exhaust.
• Inspect the fuel pump relay for proper operation. The fuel pump should operate for the first 2 seconds when turning ON the ignition.
• Test the fuel pressure. See FUEL SYSTEM DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES article.
• Inspect for water contamination in the fuel.
• Perform the fuel injector coil test. See FUEL INJECTOR COIL TEST in SYSTEM & COMPONENT TESTING article.
• Perform the fuel injector balance test. See FUEL INJECTOR BALANCE TEST in SYSTEM & COMPONENT TESTING article.
• Inspect the fuel pump check valve. See FUEL SYSTEM DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES article.
• Inspect the spark plugs for the following:
  1. Burned Electrodes
  2. Cracks
  3. Heavy Deposits
  4. Improper Gap
  5. Wear
  6. Wet Plugs
• Inspect for loose ignition coil connectors.
• Inspect for loose ignition control module connections.
• Inspect for faulty control module or ignition system grounds.
• Inspect for improper valve timing.
• Inspect for low compression. See COMPRESSION under PRELIMINARY INSPECTION & ADJUSTMENTS in BASIC DIAGNOSTIC PROCEDURES article.
• Inspect for worn rocker arms.
• Inspect for broken or weak valve springs.
• Inspect for worn camshaft lobes.
• Inspect for proper cam phaser operation.