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 severe 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 with a scan tool. The actual fuel rail pressure should be between 1.0-1.8 MPa.
If it is not, inspect for high resistance in the fuel rail pressure (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 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
. |
|
