Hard Start
WARNING: This page is about a different car, the 2004 GMC Sierra and 2004 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
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 Important Preliminary Checks in Symptoms - Engine Controls
.
- Make sure the vehicle operator is using the correct starting procedure.
|
| Fuel System Checks |
- Test for proper fuel pump relay operation.
- Test for proper fuel system pressures. Refer to Fuel System Diagnosis
.
- Test for an accurate fuel indication from the fuel tank pressure (FTP) sensor.
|
| Sensor Checks |
- Test the ECT sensor for proper operation by performing the following:
- Allow the engine temperature to reach ambient air temperature by leaving the engine OFF for several hours - overnight for most accurate results.
- Turn the ignition ON while leaving the engine OFF.
- Using a scan tool compare the ECT and IAT sensors displayed temperature.
The sensors should be within 3° C (5° F) of each other.
- Replace the ECT sensor or repair the ECT sensor circuit if the ECT is not near the expected value.
- Test the TP sensor for proper operation.
With the throttle blade fully at rest the monitored TP sensor voltage on a scan tool should be LESS than 0.85 volts.
If the TP sensor is not near the expected voltage check for the following conditions:
- A faulty TP sensor
- A faulty TP sensor circuit
- A sticking throttle shaft or linkage/cable assembly
- Test for proper operation of the crankshaft position (CKP) sensor.
- Test for proper operation of the MAP sensor - if equipped.
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