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. |
| • | Check the PCM grounds for being clean, tight and in their proper
locations. |
|
Sensor/System
|
| • | Check MAP sensor operation. |
| • | Check EGR for being loose or for a faulty gasket. Check for EGR
flow all the time. |
| • | Using a scan tool, monitor TP sensor voltage. The TP sensor voltage
should be less then 0.9 volt at rest. Also inspect the throttle body and
accelerator cables for binding. |
|
Fuel System
|
| • | Check for restricted fuel filter. |
| • | Check injector fuse(s) for being open. Replace the fuse if necessary
and inspect injector circuits for an intermittent short to ground. |
| • | Perform injector balance test. |
| • | Check items which can cause an engine to run rich (long term fuel
trim near -99%). |
| • | Check items that can cause an engine to run lean (long term fuel
trim near 100%). |
|
Ignition System
| Remove spark plugs and check for the following:
An improper spark plug gap will cause a driveability problem. The spark
plug gapping should be done using a wire gauge gap tool (J 41319). If spark
plugs are gas or oil fouled, the cause of the fouling must be determined
before replacing the spark plugs.
| • | Check for loose ignition control module ground. |
| • | Spark plugs for proper heat range. |
|
Engine Cooling System
| Check the engine thermostat for proper operation and for proper heat
range. Refer to
Thermostat Diagnosis
in Engine Cooling.
|
Additional Checks
| Check the generator
output voltage. Refer to
Charging System Check
.
|
