Checks
| Action
|
DEFINITION: Momentary lack of response as the accelerator
is pushed down. Can occur at any vehicle speed. Usually more pronounced
when first trying to make the vehicle move, as from a stop sign. May
cause the engine to stall if severe enough.
|
Preliminary
|
| • | Refer to
Symptoms
, Important
Preliminary Checks Before Starting. |
| • | Verify that the PCM grounds are clean, tight, and in the correct
locations. |
|
Sensor and System
|
| • | Check the manifold absolute pressure (MAP) sensor operation. |
| • | Check for a loose EGR and for a faulty gasket. Check for EGR
flow all the time. |
| • | Using a scan tool, monitor the throttle position (TP) sensor voltage.
The TP sensor voltage should be less than 0.9 volt at rest. Also inspect
the throttle body and the accelerator cables for binding. |
|
Fuel System
|
| • | Check for a restricted fuel filter. |
| • | Check for open fuel injector fuses. Replace the fuse if necessary.
Inspect the injector circuits for an intermittent short to ground. |
| • | Perform the fuel injector balance test. |
| • | Check the items that can cause an engine to run rich. |
| • | Check the items that can cause an engine to run lean. |
|
Ignition System
| Remove the spark plugs and check for the following conditions:
An improper spark plug gap will cause a driveability problem. The spark
plug gapping should be done with a wire gauge gap tool. If the spark plugs
are gas or oil fouled, the cause of the fouling must be determined before
replacing the spark plugs.
| • | Check for a loose ignition control module ground. |
| • | Check the spark plugs for the correct heat range. |
|
Engine Cooling System
| Check the engine thermostat for correct operation and for
the correct heat range. Refer to
Engine Fails To Reach Normal Operating Temperature
in Engine Cooling.
|
Additional Checks
| Check the generator output voltage. Refer to
Diagnostic Starting Point
in Engine Electrical
.
|
