2006/01/02 Caterpillar

New Sequence for Adjusting the Fuel Injectors {1290, 1290}

Usage:

854G 1JW

Machine Engine: 3508 (S/N: 7YG1-UP; 99W1-UP)
Machine Engine: 3508B (S/N: 2GR1-UP)

There is a new sequence for adjusting the fuel injectors. The 3508C Engine will not operate correctly if injectors are adjusted using the fuel injector adjustment sequence for the earlier 3508 and 3508B Engines.

Use the new fuel injector adjustment sequence for 3508C Engines on all 3508 and 3508B Engines. Testing has proven that using the new injector adjustment sequence on all 3508 Engines will not affect engine performance or emissions. The tables for the fuel injector adjustment sequence in the "Testing and Adjusting" manuals will be updated to reflect this change.

Current Fuel Injector Adjustment Sequence

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Table 1
Counterclockwise rotation (Standard) from the flywheel end of the engine
Cylinders to Check/Adjust
Engine	Correct Stroke For No. 1 Piston At Top Center Position ⁽¹⁾	Inlet Valves	Exhaust Valves	Injectors
3508	Compression	1-2-6-8	1-2-3-7	3-4-5-7
3508	Exhaust	3-4-5-7	4-5-6-8	1-2-6-8

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Put the No. 1 Piston at the top center (TC) position and identify the correct stroke. Refer to Testing and Adjusting, "Finding the Top Center Position for the No 1 Piston". Find the top center position for a particular stroke and make the adjustment for the correct cylinders. Remove the timing bolt. Turn the flywheel by 360 degrees in the direction of normal engine rotation. This will put the No. 1 piston at the top center (TC) position on the other stroke. Install the timing bolt in the flywheel and complete the adjustments for the cylinders that remain.

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Table 2
Clockwise rotation (Reverse) from the flywheel end of the engine
Cylinders To Check/Adjust
Engine	Correct Stroke For No. 1 Piston At Top Center Position ⁽¹⁾	Inlet Valves	Exhaust Valves	Injectors
3508	Compression	1-3-4-8	1-2-7-8	2-5-6-7
3508	Exhaust	2-5-6-7	3-4-5-6	1-3-4-8

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New Fuel Injector Adjustment Sequence

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Table 3
Counterclockwise rotation (Standard) from the flywheel end of the engine
Cylinders to Check/Adjust
Engine	Correct Stroke For No. 1 Piston At Top Center Position ⁽¹⁾	Inlet Valves	Exhaust Valves	Injectors
3508	Compression	1-2-6-8	1-2-3-7	2-3-4-7
3508	Exhaust	3-4-5-7	4-5-6-8	1-5-6-8

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Table 4
Clockwise rotation (Reverse) from the flywheel end of the engine
Cylinders To Check/Adjust
Engine	Correct Stroke For No. 1 Piston At Top Center Position ⁽¹⁾	Inlet Valves	Exhaust Valves	Injectors
3508	Compression	1-3-4-8	1-2-7-8	2-6-7-8
3508	Exhaust	2-5-6-7	3-4-5-6	1-3-4-5