GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 Sonoma Pickup - 2WD 🢒 Engine 🢒 Engine Controls - 2.2L (L43) 🢒 Hard Start

Checks

Action

DEFINITION: Engine cranks OK, but does not start for a long time. May eventually run or may start but immediately dies.

Preliminary
    • Check to see if the driver is using the correct starting procedure as described in the owners manual.
    • Refer to Symptoms .
    • Search for service bulletins.

Sensor/System
    • Check the engine coolant temperature (ECT) sensor for a skewed reading. Install a scan tool and compare the ECT with the intake air temperature (IAT) on a cold engine. The ECT and IAT should be within ± 3°C (5°F) of each other. Check the resistance of the ECT sensor if the temperature is out of range with the IAT sensor. Refer to Temperature Versus Resistance . If the ECT sensor resistance is not within the specification, refer to DTC P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage or DTC P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage .
    • Check for proper operation of the MAP sensor. Refer to Manifold Absolute Pressure Sensor Output Diagnosis .
    • Check for proper operation of the TP sensor.
    • Check for proper operation of the IAC valve.

Fuel System
    • Check for adequate fuel level.
    • Check the fuel pump relay circuit for proper operation. Refer to Fuel Pump Electrical Circuit Diagnosis .
    • Check for incorrect fuel pressure. Refer to Fuel Pump Electrical Circuit Diagnosis .
    • Check the in-tank fuel pump check valve. The in-tank fuel pump check valve may be malfunctioning, causing the fuel in the lines to drain back to the fuel tank after the engine is stopped. Refer to Fuel Pump Electrical Circuit Diagnosis .

Ignition System
    • Check for proper ignition voltage output with the spark tester J 26792 .
    • Check the spark plugs for the following conditions:
       - Wet or fuel fouled
       - Cracks
       - Wear
       - Improper spark plug gap
       - Burned electrodes or heavy deposits
    • If the spark plugs are fuel or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.
    • Check the ignition control module (ICM) for proper ground connection.
    • Check the ignition coils for cracks or carbon tracking.
    • Check the spark plug wires for proper resistance and condition.

Engine Mechanical
    • Check the engine for the following engine mechanical conditions:
       - Low compression--Refer to Engine Compression Test in Engine Mechanical.
       - Leaking cylinder head gasket
       - Worn or a incorrect camshaft
    • Refer to the appropriate diagnostic procedures in Engine Mechanical.

Additional Checks

If all procedures have been completed and no malfunctions have been found, review and inspect the following items:

    • All electrical connections within the suspected circuit and/or systems
    • Scan tool data