Diesel Engine - Dynamic Timing Specifications

Article No. 83-24-23


DIESEL (6.9L) - DYNAMIC TIMING SPECIFICATIONS


LIGHT TRUCKS 1983 E & F-SERIES

CALIBRATIONS: 4-68J-R00, 4-68X-R00

FIGURE 34:

New Exhaust Emission Calibrations 4-68J-R00 and 4-68X-R00 have been released as 1984 Running Changes. The new calibrations require different dynamic timing specifications as shown in Figure 34. Early 1984 production trucks have 3-68J-R10 and 3-68X-R10 calibrations which require 1984 dynamic timing specifications. Prior to adjusting timing on 1984 trucks, the Technician must determine the emission calibration number (which is printed on the engine code label located on the injection pump adapter (housing)) and set dynamic injection timing as specified in Figure 34.
NOTE: The following procedures should be followed when checking or setting dynamic injection timing on the 6.9L diesel engine.

1. The engine must be stabilized at normal operating temperature (192~F-212~F). This temperature is needed to insure proper fuel ignition in the precombustion chambers.
2. Prior to checking the dynamic timing with the Rotunda 78-0100 Dynamic Timing Meter, perform the meter operation check as identified in instruction manual included with the meter.
3. The Dynamic Timing Specifications Chart takes cetane value as well as altitude into consideration. For this reason, the chart, as well as the cetane tester, must be used when evaluating the timing of a 6.9L diesel.
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: "INFORMATION ONLY"

FIGURE 34:

6.9L DIESEL ENGINE DYNAMIC TIMING SPECIFICATIONS

Dynamic timing specifications for 1983 and 1984 Model vehicles are shown below: