Checking Engine Timing And Automatic Timing Advance Unit With 8T5300 Timing Indicator Group And 8T5301 Diesel Timing Adapter Group

8T5300 Timing Indicator Group
(1) 8T5250 Engine Timing Indicator. (2) 5P7366 Cable Assembly. (3) 6V2197 Magnetic Transducer. (4) 5P7362 Cable. (5) 6V2199 & 6V3093 Transducer Adapters. (6) 8K4644 Fuse.

The 8T5300 Timing Indicator Group must be used with an 8T5301 Diesel Timing Adapter Group.

8T5301 Diesel Timing Adapter Group
(7) 5P7437 Adapter. (8) 6V2198 Cable. (9) 5P7436 Adapter. (10) 6V7910 Transducer. (11) 5P7435 Adapter. (12) 6V3016 Washer.

When checking the dynamic timing on an engine, Caterpillar recommends that the service technician calculate and plot the dynamic timing specifications first on a worksheet like SEHS8140. These worksheets are available in pads of 50 sheets, order one SEHS8140. See Special Instruction, SEHS8580 for information required to calculate the timing curve. For the correct timing specifications to use, see the Engine Information Plate for the performance specification number and make reference to the TMI (Technical Marketing Information) and Fuel Setting And Related Information Fiche.

NOTE: For more information on acceptable tolerances for dynamic fuel injection timing, see Service Magazine dated 4-1-85 and 10-28-85.

After the timing values are calculated and plotted, the dynamic timing should be checked with the 8T5300 Engine Timing Indicator Group and the 8T5301 Diesel Timing Adapter Group. The engine must be operated from 1000 rpm (base rpm) and from high idle to 1000 rpm (base rpm). Unstable readings are often obtained below 1000 rpm. Record the dynamic timing at each 100 rpm and at the specified speeds during both acceleration and deceleration. Then he should plot the results on the worksheet.

Inspection of the plotted values will show if the fuel injection timing is within specifications.

Transducer In Position
(10) Injection transducer. (13) Fuel injection line for No. 1 cylinder.

1. Make reference to Special Instruction SEHS8580 for complete service information and use of 8T5300 Timing Indicator Group.

2. Loosen all fuel line clamps that hold No.1 fuel injection line and disconnect fuel injection line (13) for No.1 cylinder at the fuel injection pump. Slide the nut up and out of the way. Put 5P7436 Adapter (9) in its place and turn adapter (9) onto the fuel injection pump bonnet until the top of the bonnet threads are approximately even with the bottom of the “window” in the adapter.

3. Put the 5P7435 Adapter (11) on 6V7910 Transducer (10) and put the end of the 5P7435 Adapter (11) in the “window” of the 5P7436 Adapter (9).

4. Put fuel injection line (13) on top of 5P7435 Adapter (11). Install 5P7437 Adapter (7) and tighten to 40 N·m (30 lb ft).

Location Of Fitting
(14) Fitting.

5. Remove fitting (14) from the front housing. Install transducer adapter (5) into hole fitting (14) was removed from. Tighten only a small amount.

Transducer In Position
(3) TC magnetic transducer.

6. Push the TC magnetic transducer (3) into the transducer adapter (5) until it makes contact with the camshaft gear. Pull it back out 1.6 mm (.06 in) and lightly tighten the knurled locknut.

7. Connect the cables from the transducers to the Engine Timing Indicator. Make a calibration check of the indicator. For calibration procedure, make reference to Special Instruction SEHS8580.

8. Start the engine and let it reach operating temperature. Then run the engine at approximately one-half throttle for eight to ten minutes before measuring timing.

9. Run the engine at the speeds required to check low idle, timing advance and high idle. Record the engine timing indicator readings. If the engine timing is not correct, make reference to Fuel System Adjustments: On Engine, Fuel Injection Pump Timing (Timing Pin Method) for static adjustment of the fuel injection pump drive.

10. If the timing advance is still not correct, or if the operation of the advance is not smooth, make a repair or replacement of the automatic advance unit. There is no adjustment to the unit.

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