Injection Timing: Adjustments

Fig. 20 Injection pump timing marks:

WITHOUT TIMING METER
1. Remove fast idle bracket and solenoid, if equipped, from injection pump.
2. Loosen 3 injection pump-to-mounting adapter attaching nuts using tool No. T83T-9000-B or equivalent.
3. Rotate injection pump, using tool No. T83T-9000-C or equivalent, to align timing marks on pump mounting flange and adapter, Fig. 20, to within .030 inch.
4. Remove rotating tool and torque pump attaching nuts to 14 ft. lbs.
5. Ensure timing marks are still aligned, then install fast idle bracket and solenoid, if equipped.

Fig. 21 Timing meter magnetic pickup installation:

Fig. 22 Timing meter luminosity probe installation:

Fig. 23 Injection pump timing specifications. 1983---84:

W/TIMING METER 78-0100
1. Start engine and run until normal operating temperature is reached. Engine temperature must be stabilized between 192 and 212°F to ensure proper fuel ignition in the precombustion chambers. If temperature is less than 192°F, fuel ignition is delayed and the timing meter will record an inaccurate injection value.
2. Shut engine off, then install timing meter by inserting magnetic pickup into timing pointer probe hole, Fig. 21. Insert magnetic pickup until it almost touches vibration damper.
3. Remove No. 1 glow plug, then install luminosity probe, Fig. 22, and torque to 12 ft. lbs. Install photocell over probe.
4. Connect timing meter to battery and adjust offset on meter. On 1986---87 models, dial in 20° offset on meter, then disconnect cold start advance solenoid connector from solenoid terminal. Ensure wire leads are positioned away from drive belts.
5. Start and run engine with transmission in Neutral and rear wheels raised off ground.
6. Set engine speed to 1400 RPM, using tool No. 14-032 or equivalent, with all accessories off.
7. Observe injection timing on timing meter and compare to values listed in chart, Figs. 23 and 24. If timing is within specifications, proceed to step 14. If timing is not within specifications, proceed to step 8. Fuel cetane is a rating of a fuel's ability to ignite under compression ignition conditions. Fuels with high cetane values will ignite faster than fuels with low cetane values. A tester is supplied with timing meter to determine cetane value of fuel.
8. On 1986---87 models, apply battery voltage to cold start advance solenoid terminal, then readjust engine speed to 1400 RPM, if necessary, and observe timing on meter. If timing is not advanced at least 2.5° from reading obtained in step 7, replace fuel injection pump.
9. Shut engine off and note timing mark alignment.
10. Remove fast idle bracket and solenoid, if equipped, from injection pump.
11. Loosen 3 injection pump-to-mounting adapter attaching nuts using tool No. T83T-9000-B or equivalent.
12. Rotate injection pump, using tool T83T-9000-C or equivalent. Rotate pump clockwise (as viewed from front of engine) to retard, or counterclockwise to advance timing. Each 2° of timing is equal to approximately .030 inch of timing mark movement.
13. Remove rotating tool and torque pump attaching nuts to 14 ft. lbs. Start engine and recheck timing. If timing is still not within specifications, repeat adjustment.
14. Shut engine off and remove timing meter, then install glow plug and torque to specifications.
15. Install fast idle bracket and solenoid, if equipped.