Checks
| Action
|
DEFINITION: The engine
cranks normally, but does not start in a normal amount of time. The engine
does eventually run, or may start but immediately dies.
|
Preliminary Checks
|
| • | Make sure the vehicle's operator is using the correct starting
procedure. |
|
Sensor Checks
|
| • | Check the engine coolant temperature (ECT) sensor with the scan
tool. Compare the engine coolant temperature with the ambient air temperature
on a cold engine. If the coolant temperature reading is more than
5 degrees more or less than the ambient air temperature on a cold engine,
check for a high resistance in the coolant sensor circuit. |
| • | Check the throttle position (TP) sensor. If a sticking throttle
shaft or binding linkage causes a high TP sensor voltage, the control
module will not control the idle. While monitoring the TP sensor voltage,
the scan tool should display less than 0.85 volt with the throttle
closed. |
|
Fuel System Checks
|
| | Important: A damaged fuel pump check valve will allow the fuel in the lines to
drain back to the tank after the engine stops.
|
| • | Check for water contamination in the fuel. |
|
Ignition System Checks
|
| • | Check for the proper ignition voltage output with J 26792
or the equivalent. |
| • | Check the spark plugs for the following conditions: |
| • | Check for bare or shorted ignition wires. |
| • | Check for moisture in the distributor cap, if applicable. |
| • | Check for loose ignition coil connections. |
| • | Check for loose ignition control module connections. |
| • | Check for a faulty control module or ignition system grounds. |
|
Engine Mechanical Checks
|
| • | Check for the following: |
| - | An incorrect valve timing |
| - | Any broken or weak valve springs |
| - | Any worn camshaft lobes. Refer to Engine Mechanical. |
| • | Check the intake and exhaust manifolds for casting flash. Refer
to Engine Mechanical. |
|
Additional Check
|
|
