GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2000 🢒 Prizm 🢒 Engine 🢒 Engine Controls - 1.8L 🢒 Hard Start

Hard Start

Checks

Action

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

Preliminary Checks
    • Refer to Symptoms .
    • Check that the driver is using the correct starting procedure.

Sensor Checks
    • Check the engine coolant temperature (ECT) sensor using a scan tool to compare the engine coolant temperature with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5°C (41°F) more or less than the ambient air temperature on a cold engine, check for a high resistance in the coolant sensor circuit or in the sensor. Refer to Temperature Versus Resistance .
    • Check the throttle position (TP) sensor. A sticking throttle shaft or a binding throttle linkage will causes a high TP sensor voltage. Under these conditions the PCM may not control the idle. Monitor the TP sensor angle with the scan tool. The indicated angle should be approximately 9-11 percent with throttle closed.
    • Check the mass air flow (MAF) sensor with a scan tool. Observe the MAF sensor readings while cranking the engine. A normal MAF value is approximately 1.8-4.0 g/s.

Fuel System Checks
    • Check the fuel pump relay for correct operation. Observe the fuel pump relay operation on a scan tool while cranking the engine. Refer to Fuel System - Circuit Opening Relay Diagnosis .
    • Check the fuel pressure. Refer to Fuel System Diagnosis .
    • Check for water contamination in the fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Check for no Crank signal at the PCM connector C3 terminal 11 if the vehicle is slower to start in cold weather. Observe the Starter Switch parameter on a scan tool while cranking the engine. The PCM provides slightly more fuel for engine start up when receiving the Crank input.
    • Check the fuel pump check valve. A faulty fuel pump check valve will allow the fuel in the lines to drain back into the tank after stopping the engine. This condition is especially troublesome on Hot Soak restarts. In order to check for this condition perform the following steps:
        1. Turn OFF the ignition.
        2. Install the fuel pressure gauge. Refer to Fuel Pressure Gage Installation and Removal .
        3. Pressurize the fuel rail by turning the ignition key ON and OFF a few times.
        4. Turn the ignition key ON and observe the fuel pressure. The fuel pressure has to remain more than 147 kPa (24 psi).

Ignition System Checks
    • Check for the proper secondary voltage output with a J 26792 spark tester or equivalent.
    • Check the spark plugs for correct operation and performance. Refer to Spark Plug Visual Diagnosis .
    • Check for bare or shorted ignition system wires.
    • Check for loose ignition coil connections.

Additional Checks
    • An idle air control (IAC) system that is malfunctioning can cause a hard start condition. Hold the throttle open slightly while starting the engine. After the vehicle is started the scan tool can be used to check the operation of the IAC valve. Operate the IAC valve with the scan tool while checking for a smooth increase and decrease in engine speed. If engine speed can be controlled, the IAC system is functioning normally. If engine speed can not be controlled with the scan tool refer to Diagnostic Aids in DTC P0505 Idle Control System .
    • Check the Service Bulletins for any updates.