Hard Start. Chevrolet Tracker

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2004 🢒 Tracker - 4WD 🢒 Engine 🢒 Engine Controls - 2.5L (LE8) 🢒 Hard Start

Checks

Action

DEFINITION: The engine cranks OK, but does not start for a long time. The engine does eventually run, or the engine may start but immediately stalls.

Preliminary Checks

Refer to Diagnostic System Check - Engine Controls .

•	Refer to Symptoms - Engine Controls .

•	Check that the driver is using the correct starting procedure.

Sensor Checks

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Inspect for a shifted or fixed engine coolant temperature (ECT) sensor. With the scan tool, compare the engine coolant temperature reading of a cold engine with the ambient air temperature. A difference of more than 5°C (9°F) in temperatures may indicate high resistance in the coolant sensor circuit or in the sensor. Refer to Temperature Versus Resistance .

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Check the throttle position (TP) sensor. A sticking throttle shaft or a binding throttle linkage will causes a high TP sensor voltage or an open throttle indication. The PCM may not control the idle if a high TP voltage is present. Monitor the TP sensor voltage with the scan tool or a DMM. The indicated voltage should be less than 1.0 volts with the throttle closed.

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Check the camshaft position (CMP) sensor engine reference signal with a scan tool. Observe the Engine Speed parameter while cranking the engine. The scan tool should indicate a steady 200-300 RPM while cranking. If erratic values, such as sudden spikes in the engine speed, are displayed, the engine reference signal is not stable enough for the engine to start and run properly.

Fuel System Checks

•	Check the fuel pump relay for correct operation. The fuel pump should operate for 2 seconds when turning ON the ignition. Refer to Fuel Pump Electrical Circuit Diagnosis .

•	Check for the correct fuel pressure. Refer to Fuel System Diagnosis .

•	Check for water contaminated fuel or inferior quality fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

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Check the operation of the fuel pump check valve. A faulty check valve will allow the fuel in the fuel lines to drain back into the fuel tank after stopping the engine. This condition can cause hard starts, especially on hot soak restarts. In order to check for this condition, perform the fuel pressure check in Fuel System Diagnosis .

Ignition System Checks

•	Check for adequate secondary ignition voltage with a J 26792 Spark Tester or an equivalent. Refer to Electronic Ignition (EI) System Diagnosis .

•	Check for the correct ignition timing. Refer to Ignition System Timing Adjustment .

•	Check for damaged or worn spark plugs. Refer to Spark Plug Inspection .

•	Check for loose ignition coil connections.

•	Check all the ignition system electrical connections.

Additional Checks

•	Inspect the PCM grounds and engine grounds for clean and tight connections in the correct locations. Refer to Engine Controls Schematics .

•	Check for the correct operation of the idle air control (IAC) system. Refer to Idle Air Control (IAC) System Diagnosis .

•	Observe that the Starter Switch parameter on the scan tool indicates CRANKING, while the engine is cranking. A faulty switch signal may cause an extended crank time. The PCM uses the Starter Switch signal to deliver a richer fuel injector pulse during vehicle cold start.

•	Check for the correct operation of the EGR valve. Refer to Exhaust Gas Recirculation (EGR) System Diagnosis .

•	Check for service bulletin updates or information.