GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Monte Carlo 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 Hard Start

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

Preliminary
    • Search for bulletins.

Sensor/System
    • Check Engine Coolant Temperature (ECT) sensor for being shifted in value. Connect a Scan Tool and compare Engine Coolant Temperature with Intake Air Temperature 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 the 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 Diagnosis.
    • Check Mass Air Flow sensor for proper installation and conditions. A MAF sensor with a damaged honeycomb may cause a hard start. Refer to MAF Sensor Repair Mass Airflow Sensor Replacement .
    • Using a scan tool, check IAC operation. Refer to Idle Air Control (IAC) System Diagnosis .
    • Check the EGR system for proper sealing/connections and operation. Refer to Exhaust Gas Recirculation (EGR) System Description .

Fuel System
    • Check the fuel pump relay circuit for proper operation. Refer to Fuel Pump Electrical Circuit Diagnosis .
    • Check for low fuel pressure. Refer to Fuel System Pressure Test .
    • Check for faulty fuel injectors using the following procedures:
       -  Fuel Injector Balance Test
    • Check for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis Procedure.

Ignition System
    • Check for proper ignition voltage output using the following steps:
       - Clip the spark tester J 26792 to engine ground.
       - Connect one end of a spark plug wire to the spark tester; leave the other end of the spark plug wire to the coil being tested.
       - Connect one end of another spark plug wire to the other coil tower; connect the other end of the spark plug wire to ground.
       - Crank the engine while observing the spark tester; a spark should be observed.
       - Repeat the above steps for each coil.
    • If spark is not present at the plugs(s), check for the following conditions:
       - Inspect the coil(s) for cracks, carbon tracking/arcing, or a secondary resistance value outside the specified range.

Coil Resistance
5000 - 8000 ohms (5K - 8K ohms)

       - Inspect the spark plug wires for signs of arcing/cross firing, cracks, carbon tracking, plug boot damage, pinched, improper routing, or a resistance value outside the specified range.

Spark Plug Wire Resistance
600 ohms per ft.

   Important: Spraying the secondary ignition wires with a light mist of water may help locate an intermittent problem. Ignition components will arc to ground when a secondary component is malfunctioning.

       - Inspect for a malfunctioning ignition control module.
       - Inspect the ignition system wiring for loose ignition module feed or ground connection, or damaged system wiring.
    • Remove spark plugs and check for the following:
       - Fouled plugs
       - Cracks

   Important:: If carbon tracking is detected on any component, replace that component and it's mate.

       - Carbon tracking on the porcelain and pitting on the plug wire contact
       - Wear
       - Improper gap
       - Burned or damaged electrodes
       - Improper heat range or reach. Refer to Maintenance Items .
    • If spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.
    • Check for the following intermittent ignition system conditions:
       - CKP Sync or CKP 18X Signal.
       - Ignition Feed circuit or sensor ground circuit to the crankshaft position sensor or camshaft position sensor.
       - 3X reference signal.
       - camshaft position signal,

Engine Mechanical
    • Excessive oil in combustion chamber-Leaking valve seals.
    • Low cylinder compression.
    • For incorrect basic engine parts. Inspect the following:
       - Cylinder heads
       - Camshaft and valve train components
       - Pistons, etc.