GM Service Manual Online
For 1990-2009 cars only

Checks

Action

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

Preliminary

Perform the Diagnostic System Check - Engine Controls .

Sensor/System

A variety of sensor or physical conditions may result in a hard start condition without setting a DTC. In order to determine if any of these conditions exist, perform the following actions:

    • Compare scan tool data to a known good vehicle or refer to Scan Tool Data List .
    • Check for a restricted exhaust. Refer to Restricted Exhaust in Engine Exhaust.

Fuel System

A variety of fuel system conditions may result in a hard start condition without setting a DTC. In order to determine if any of these conditions exist, perform the following actions:

    • Refer to Fuel System Diagnosis .

Ignition System

A variety of ignition system conditions may result in a hard start condition without setting a DTC. In order to determine if any of these conditions exist, perform the following actions.

Refer to Electronic Ignition (EI) System Diagnosis .

Engine Mechanical

A variety of engine mechanical conditions may result in a hard start condition without setting a DTC. In order to determine if any of these conditions exist, perform the following actions.

Refer to Engine Compression Test in Engine Mechanical.

If incorrect compression is detected, check the following items:

    • Carbon Build-Up
    • Cam Timing
    • Oil Fouling
    • Incorrect Parts
    • Bent Pushrods
    • Rocker Arms
    • Valve Springs
    • Cam Lobes
    • Intake/Exhaust Manifold Flashing
    • Head Gaskets