ENGINE MECHANICAL
Before performing any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.
VALVE CLEARANCE
Note. All models are equipped with hydraulic lifters. Adjustments are not required.
CHECKING/ADJUSTING INJECTION TIMING
Original factory injection pump timing is marked with a static timing mark, a line scribed across both the pump mounting flange and the front cover. This static timing mark should be used as a reference. If timing mark is not present on mounting flange, scribe a line to assist in how far injection pump needs to be rotated.
- Start and warm engine to normal operating temperature. Connect Tech 1 scan tool. Set scan tool to OUTPUT TEST/INJ PUMP mode. Activate TDC TIME SET. The DESIRED INJ TIM value will read zero. NOTE: If engine stalls when TDC TIME SET is activated, turn engine off. Loosen injection pump nuts. Slightly rotate injection pump toward driver's side of vehicle. Tighten injection pump nuts. Repeat step 1).
- Ensure engine is running, then check ACTUAL INJ TIM for proper timing specification. See DIESEL INJECTION PUMP TIMING (DEGREES BTDC @ RPM) table. If timing needs adjustment, turn engine off to avoid engine damage, then adjust injection pump. A 1-mm pump movement equals about a 2 degrees timing change.
| Application | Man. Trans. | Auto. Trans. |
|---|---|---|
| 6.5L | 3.5 @ Idle | 3.5 @ Idle |
DIESEL INJECTION PUMP TIMING
TDC OFFSET LEARN PROCEDURE
This procedure is only used when one of following conditions exists
- DTC 1214 is set.
- Engine has been replaced.
- Front engine cover has been replaced.
- PCM and injection pump have been replaced.
- Start and warm engine to normal operating temperature. Connect Tech 1 scan tool. Clear all DTCs. Turn ignition on, with engine off. Using scan tool, select OUTPUT TEST/INJ PUMP mode. Activate TDC OFFSET LEARN.
- If learned TDC OFFSET reading is between -.25 and -.75 degree, procedure is complete. If reading is not as specified, hold accelerator pedal in wide open throttle position for at least 45 seconds. Turn ignition off for 30 seconds. Start engine. TDC OFFSET reading should be zero. If reading is not zero, repeat step 1).
- Start and warm engine to normal operating temperature. PCM will learn new TDC OFFSET when normal operating temperature is obtained and engine speed is less than 1500 RPMs. New TDC OFFSET will overwrite previous reading. If new learned TDC OFFSET reading is not between -.25 and -.75 degree, turn ignition off.
- Slightly rotate injection pump and repeat step 1). A 1-mm pump movement equals about 2 degrees timing. To achieve a positive reading, rotate pump toward driver's side. To achieve a negative reading, rotate pump toward passenger's side.
IDLE SPEED
Idle speed is not adjustable. PCM controls all fuel delivery/modes based on inputs from AAP, ECT and BARO sensors. System is equipped with an electronic fuel injection pump.
THROTTLE POSITION (TP) SENSOR
Throttle control is electronic with NO mechanical link from engine to accelerator pedal. The PCM monitors the position of accelerator pedal based on signals from a nonadjustable Accelerator Pedal Position (APP) module. The APP is mounted above the accelerator pedal.