Hard Start

Inspection/Test	Action
DEFINITION: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately stalls.
Preliminary	Perform the Diagnostic System Check - Vehicle in Vehicle DTC Information
Sensor/System	Test engine coolant temperature (ECT) sensor for being shifted in value. Connect a scan tool and compare ECT with intake air temperature (IAT) on a cold engine. The ECT and IAT should be within +/- 3° C (5° F) of each other. Test the resistance of the ECT sensor if the temperature is out of range with the IAT sensor. Refer to Temperature vs Resistance . If the ECT sensor resistance is not within the specification, or DTC P0113 . Monitor the 24X crank sensor and CMP sensor signal present parameters on a scan tool. If both are not responding, test the sensor feed circuit. Both sensors use a separate feed circuit but are internally connected to power. Test all CKP sensor A and CMP sensor circuits for intermittents. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Monitor the 3X crank sensor parameter on the scan tool. If the 3X crank sensor parameter is not responding, inspect the CKP sensor B and circuits for intermittents. Inspect the ignition control (IC) circuit, IC timing control circuit, low resolution engine speed signal circuit and the low reference circuit for intermittents. If these circuits become open, or shorted, they may not set a DTC immediately, but are capable of causing driveability complaints. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Inspect the mass air flow (MAF) sensor for proper installation and conditions. A MAF sensor with a damaged honeycomb may cause a hard start. Inspect the air intake ducts for being collapsed, damaged areas, looseness, improper installation, or leaking, especially between the MAF sensor and the throttle body. Using a scan tool, test the idle air control (IAC) operation. Command the engine RPM to 1,500 RPM and back to the starting RPM. If the engine RPM does not change when commanded refer to DTC P0506 and DTC P0507 to diagnose the IAC system. Inspect the exhaust gas recirculation (EGR) system for proper sealing/connections and operation. Refer to Exhaust Gas Recirculation (EGR) System Description .
Fuel System	Test the fuel system circuits for proper operation. Refer to Fuel Pump Electrical Circuit Diagnosis . Test for low fuel pressure. Refer to Fuel System Diagnosis . Test for faulty fuel injectors. Refer to Fuel Injector Balance Test with Special Tool , Fuel Injector Balance Test with Tech 2 , Fuel Injector Coil Test test procedures. Inspect for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (With Special Tool) .
Ignition System	Inspect for proper ignition voltage output using the following steps: Attach the J 26792 Spark Tester to engine ground. See Special Tools . Connect the spark plug end of the spark plug wire to the J 26792 . See Special Tools . Connect the other end of the spark plug wire to the coil being tested. Connect the spark plug end of the companion spark plug wire to ground. The companion spark plug wire is the wire attached to the corresponding coil tower. Crank the engine while observing the J 26792 . See Special Tools . A spark should be observed. Repeat the above steps for each coil. If spark is not present at the coils, inspect for the following conditions: Coils-Cracks, carbon tracking/arcing, or a resistance value outside the specified range. Coil Resistance: 5,000-8,000 Ω Spark Plug wires-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: 9,842 Ω per meter (3,000 Ω per foot) IMPORTANT: Spraying the secondary ignition wires with a light mist of water may help locate an intermittent condition. Ignition voltage arcs to ground when a secondary component is faulty. Defective ignition module Ignition system wiring-Loose ignition module feed or ground connection, or damaged system wiring. Remove spark plugs and inspect for the following conditions: Fouled plugs Cracks Wear Improper gap Burned or damaged electrodes Improper heat range or reach If spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs. Refer to Spark Plug Inspection .
Engine Mechanical	Excessive oil in combustion chamber-Leaking valve seals. Refer to Oil Consumption Diagnosis in Engine Mechanical. Low cylinder compression. Refer to Engine Compression Test in Engine Mechanical. Inspect for incorrect engine parts, such as the following basic components: The cylinder heads The camshaft and valve train components The pistons, etc. Refer to Symptoms - Engine Mechanical in Engine Mechanical.