Hard Start

Inspections	Action
DEFINITION: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies.
Preliminary	Refer to Important Preliminary Inspections Before Starting in Symptoms - Engine Controls . Inspect the engine control system grounds for being clean, tight, and in the correct locations. Refer to Power and Grounding Component Views in Wiring Systems and Engine Controls Schematics . Ensure the resistance between the engine control module (ECM) housing and the battery negative cable is less than 0.5 ohms. Verify that the ECM and ECM bracket fasteners are at the correct torque. Search for service bulletins that may address this condition.
Sensor/System	Confirm the correct operation of the theft deterrent system. Refer to Symptoms - Theft Deterrent in Theft Deterrent. IMPORTANT: Allow the engine to cool before performing this test. Inspect the engine coolant temperature (ECT) sensor for being skewed in value. Compare the ECT sensor value to the intake air temperature (IAT) sensor value on a cold engine. The ECT and IAT sensor values should be within ± 3°C (5°F). If the ECT sensor is out of range with the IAT sensor, test the resistance of the ECT sensor. Refer to Temperature Versus Resistance - Engine Coolant Temperature Sensor for resistance specifications. Replace the ECT sensor if the resistance is not within the specification. Refer to Engine Coolant Temperature Sensor Replacement . If the sensor is within the specification, repair the high resistance in the ECT signal circuit. Inspect the crankshaft position (CKP) sensor for the correct resistance. The sensor resistance may be out of range after a hot soak. Measure that the resistance remains within 700-1,200 ohms at all temperatures.
Fuel System	Test the fuel pump relay operation. The fuel pump should turn ON for 2 seconds when the ignition is turned ON. Refer to Fuel Pump Electrical Circuit Diagnosis . Test for incorrect fuel pressure. Refer to Fuel System Diagnosis . Test for a restricted fuel filter. Refer to Fuel System Diagnosis . Test for leaking fuel injectors. Refer to Fuel System Diagnosis . Test for plugged or restricted injectors. Refer to Fuel Injector Balance Test with Special Tool . Test for a contaminated fuel condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis (w/o Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (w/Special Tool) .
Ignition System	Inspect for the correct installation of the ignition coil seals. Incorrect installation may allow water to enter the spark plug area. Inspect for moisture and corrosion. Test the ignition voltage output with J 26792 Spark Tester. See Special Tools . If you suspect an ignition system condition exists, refer to Electronic Ignition (EI) System Diagnosis . Remove the spark plugs and inspect for the following conditions: Correct heat range Wet plugs Cracks Wear Improper gap Burned electrodes Heavy deposits Refer to the following procedures: Spark Plug Replacement Ignition System Specifications Spark Plug Inspection If the spark plugs are gas, coolant or oil fouled, determine the cause before replacing the spark plugs. Refer to the following procedures: For diagnosis of a rich condition, refer to DTC P2178 or DTC P2188 . For diagnosis of coolant contaminated spark plugs, refer to Loss of Coolant in Engine Cooling. For diagnosis of oil fouled spark plugs, refer to Oil Consumption Diagnosis in Engine Mechanical - 3.6L (LY7). Inspect the spark plug boots and terminals for burning or micro-arcing, corrosion, and damage to the insulation.
Engine Mechanical	Inspect for the following engine mechanical conditions: Excessive oil in combustion chamber or leaking valve seals Low cylinder compression Sticking or leaking valves Worn camshaft lobes Camshaft timing Broken valve springs Excessive carbon buildup in the combustion chambers. Clean the chambers with top engine cleaner. Follow the instructions on the can. For more information, refer to the following procedures in Engine Mechanical - 3.6L (LY7): Oil Consumption Diagnosis Engine Compression Test Camshaft Timing Drive Chain Alignment Diagram (Third Design) or Camshaft Timing Drive Chain Alignment Diagram (Fourth Design) Setting Camshaft Timing Symptoms - Engine Mechanical Inspect the following components for incorrect basic engine parts: Camshafts Cylinder heads Pistons, connecting rods, or bearings. Refer to the following procedures in Engine Mechanical - 3.6L (LY7): Camshaft Timing Drive Components Cleaning and Inspection Camshaft Cleaning and Inspection Cylinder Head Cleaning and Inspection Piston, Connecting Rod, and Bearings Cleaning and Inspection