Difficult To Start: Ascender
NOTE:
If engine cranks but will not run, see appropriate ENGINE CRANKS BUT WILL NOT RUN testing in BASIC DIAGNOSTIC PROCEDURES
article.
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:
- Burned Electrodes
- Cracks
- Heavy Deposits
- Improper Gap
- Wear
- 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.