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
|
| • | Make sure the vehicle operator is using the correct starting procedure. |
|
Fuel System Checks
|
| • | Inspect for a leaking low pressure lock-off solenoid. |
| • | Test for proper fuel pump relay operation. |
| • | Inspect the gas distribution adaptor (GDA) for proper installation
and for leakage. |
| • | Test for an open natural gas operation (NGO) Enable circuit. |
| • | Test for an accurate fuel indication from the fuel pressure sensor
(FPS). |
|
Sensor Checks
|
| • | Test the ECT sensor for proper operation by performing the following: |
| 1. | Allow the engine temperature to reach ambient air temperature
by leaving the engine OFF for several hours (overnight for most accurate results). |
| 2. | Turn the ignition ON while leaving the engine OFF. |
| 3. | Using a scan tool compare the ECT and IAT sensors displayed temperature. |
The sensors should be within 3°C (5°F) of each other.
| 4. | 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 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). |
|
