Inspection
| Action
|
DEFINITION: The vehicle has a momentary lack of response when pushing down on
the accelerator. The condition can occur at any vehicle speed. The condition is usually
most severe when trying to make the vehicle move from a stop. If sever enough, the
condition may cause the engine to stall.
|
Preliminary Inspection
| Refer to
Symptoms - Engine Controls
.
|
Fuel System Inspection
|
| • | Inspect for high fuel supply system vacuum after a cold start or during
moderate or full throttle acceleration. If the vacuum jumps above specification, there
is a restriction in the fuel system. |
|
Sensor Inspection
|
| • | Turn ON the ignition with the engine OFF. Observe the actual fuel rail
pressure (FRP) with a scan tool. The actual FRP should be between 1.1-1.8 MPa.
If it is not, inspect for high resistance in the FRP sensor circuits or the FRP sensor.
Refer to
Circuit Testing
and
Wiring Repairs
in Wiring Systems. |
| • | Test for an intermittent FRP sensor signal by wiggling the harness between
the sensor and the engine control module (ECM) with the ignition ON and the engine
OFF, while monitoring the parameter with a scan tool. |
| • | Observe the FRP sensor and the fuel pressure regulator commanded percent
at idle. FRP should be near 40 MPa, and commanded percent should be near 40 percent.
If the command is high, a fuel pressure or sensor exists. |
| • | Inspect the crankshaft position (CKP) sensor reluctor wheel. Remove the
CKP sensor and attempt to move the reluctor wheel front to back or side to side with
a probe. If there is any movement the reluctor wheel retaining bolts are loose. |
|
Additional Inspection
|
| • | Review the service bulletins for control module software updates. |
| • | Compare the scan tool data at idle with the scan tool data list. Refer
to
Scan Tool Data List
. |
|
