3508, 3512 and 3516 Engines Caterpillar


Fuel System

Usage:

3508 5PW


Checking Engine Cylinders Separately

The temperature of an exhaust manifold port can be an indication of the condition of a unit injector. Low temperature at an exhaust manifold port is an indication of no fuel to the cylinder. This can possibly be an indication of an injector with a defect. An extra high temperature at an exhaust manifold port can be an indication of too much fuel to the cylinder. High temperatures may also be caused by an injector with a defect.

Refer to Testing And Adjusting, "Measurement Of Exhaust Temperature" for the procedure to check the exhaust manifold port temperatures.

Fuel Pressure

The 1U-5470 Engine Pressure Group can be used in order to check the engine fuel pressures.




Illustration 1g00284796

1U-5470 Engine Pressure Group

(1) Pressure indicators. (2) Zero adjustment screw. (3) Pressure indicator. (4) Pressure tap. (5) Pressure indicator.

This tool group has an indicator that is used to read the pressure in the fuel manifolds. The Special Instruction, SEHS8907 is with the tool group.

The fuel pressure regulating valve keeps the pressure in fuel manifolds between 415 to 450 kPa (60 to 65 psi).




Illustration 2g00336458

Front View Of Engine (Typical Example)

(6) Port.

Connect the 1U-5470 Engine Pressure Group at the location of port (6) .

Engine Rotation

The SAE standard engine crankshaft rotation is counterclockwise from the flywheel end of the engine.

Finding Top Center Position For No. 1 Piston

Table 1
Tools Needed     Quantity    
9S-9082 Engine Turning Tool     1    



Illustration 3g00284799

Timing Bolt Location (Typical Example)

(1) Cover. (2) Timing bolt. (3) Plug.

  1. Remove cover (1) and plug (3) from the right front side of the flywheel housing.



    Illustration 4g00284800

    Timing Bolt Installation (Typical Example)

    (2) Timing bolt. (4) 9S-9082 Engine Turning Tool .

  1. Put timing bolt (2) through the timing hole in the flywheel housing. Use the 9S-9082 Engine Turning Tool (4) and a 1/2 inch drive ratchet wrench in order to turn the flywheel in the direction of normal engine rotation. Turn the flywheel until the timing bolt engages with the hole in the flywheel.

    Note: If the flywheel is turned beyond the point of engagement, the flywheel must be turned in the direction that is opposite of normal engine rotation. Turn the flywheel by approximately 30 degrees. Then turn the flywheel in the direction of normal engine rotation until the timing bolt engages with the threaded hole. This procedure will remove the play from the gears when the No. 1 piston is on top center.

  1. Remove the valve cover for the No. 1 cylinder head.

  1. The inlet and exhaust valves for the No. 1 cylinder are fully closed if No. 1 piston is on the compression stroke and the rocker arms can be moved by hand. If the rocker arms cannot be moved and the valves are slightly open, the No. 1 piston is on the exhaust stroke. Refer to Testing And Adjusting, "Crankshaft Positions For Unit Injector Lash And Valve Lash Setting". Find the cylinders that need to be checked or adjusted for the stroke position of the crankshaft after the timing bolt has been installed in the flywheel.

    Note: When the actual stroke position is identified and the other stroke position is needed, remove the timing bolt from the flywheel. Turn the flywheel by 360 degrees in the direction of normal engine rotation.

Camshaft Timing

Timing Check

Table 2
Tools Needed     Quantity    
9S-9082 Engine Turning Tool     1    



Illustration 5g00284801

Location Of Timing Pins (Typical Example)

(1) Timing hole. (2) Timing pin.

  1. Remove rear camshaft covers from both sides of the engine.

  1. Make reference to Finding Top Center Position For No. 1 Piston.

    Note: When the timing bolt is installed in the flywheel, it is not necessary to remove the No. 1 valve cover in order to find the compression stroke. Both rear camshaft covers must be removed in order to check the timing.

  1. When the timing bolt is installed in the flywheel, look at the rear end of the camshaft. If the timing ring is visible, then the No. 1 piston is on the compression stroke. If the timing ring is not visible, feel the back of the camshaft for the groove. If the groove is at the back of the camshaft, the flywheel must be turned by 360 degrees in order to put the No. 1 piston on the compression stroke.



    Illustration 6g00284802

    Installation Of Timing Pins (Typical Example)

    (2) Timing pin. (3) Camshaft (RH).

  1. When the timing bolt is installed in the flywheel and the No. 1 piston on the compression stroke, remove the timing pins (2) from the storage positions.

  1. Install the timing pins (2) through the timing holes (1) in the engine block. Install the timing pins into the groove in the camshaft (3) on each side of the engine. In order to time the engine correctly, the timing pins must fit into the groove of each camshaft.

  1. If timing pins (2) do not engage in the grooves of both camshafts, the engine is not in time, and one or both camshafts must be adjusted.

  1. Both camshafts are adjusted in the same manner. Refer to Testing And Adjusting, "Timing Adjustment" for the procedure to put the camshafts in time with the crankshaft.


NOTICE

If a camshaft is out of time more than 18 degrees, the valves can make contact with the pistons. This will casue damage that will make engine repair necessary.


Timing Adjustment

Table 3
Tools Needed     Quantity    
9S-9082 Engine Turning Tool     1    
6V-3010 Puller Group     1    
8S-9089 Bolts     2    
5P-1076 Hard Washers     2    

Note: The timing must be checked before the timing adjustments are made. See Testing And Adjusting for this procedure.

After the Timing Check procedure is complete, the timing bolt will be engaged in the flywheel. The No. 1 piston will be at the top center (TC) position.




Illustration 7g00284803

Loosen Rocker Shafts (Typical Example)

(1) Bolt. (2) Rocker shaft.




Illustration 8g00284804

Camshaft Drive Gears (RH Side)

(3) Drive gear. (4) Plate. (5) Bolt.

  1. Remove all of the valve covers on the side for the camshaft adjustment. Now loosen bolts (1) that hold rocker shafts (2) to valve cover bases until all rocker arms are free from the injectors and the valves.

    Note: The above procedure must be done before camshaft drive gear (3) is pulled off the camshaft taper.

  1. Remove the covers from the flywheel housing.



    Illustration 9g00284805

    Camshaft Drive Gears (LH Side)

    (5) Bolt. (8) Timing ring.




    Illustration 10g00284806

    Storage Position For Timing Pins (Typical Example)

    (6) Timing pin. (7) Cover.

  1. Remove the bolts (5), plate (4) on the RH side, and the timing ring (8) on LH side.

  1. Install the 6V-3010 Puller Group, two 8S-9089 Bolts, and two 5P-1076 Hard Washers. Loosen drive gears (3) from the taper on the camshafts. Remove the tooling and the gears.

  1. Remove timing pins (6) from the storage position on each side of the engine.



    Illustration 11g00284807

    Camshaft Timing Pin Installed (Typical Example)

    (6) Timing pin.

  1. Turn the camshafts until timing pins (6) can be installed through the engine block and into the grooves (slots) in the camshafts.

  1. Put camshaft drive gears (3) in position on the camshafts.

  1. Use hand pressure to turn and hold camshaft drive gears in the opposite direction of the rotation. This removes all gear clearance (backlash) between camshaft drive gears (3) and the idler gears.

  1. Install plate (4) on the RH side. Install the timing ring (8) on the LH side in order to hold the camshaft drive gears (3) to each camshaft.

  1. Tighten the bolts (5) in steps to a torque of 360 ± 40 N·m (270 ± 30 lb ft).

  1. Tap the bolts (5). Tighten the bolts to a torque of 360 ± 40 N·m (270 ± 30 lb ft).

    Note: If necessary, repeat Step 11until the torque does not change.

  1. Install the gaskets and covers on the flywheel housing.

  1. Remove timing pins (6) from the camshafts. Install timing pins (6) in the storage positions. Install covers (7) over the camshafts and timing pins.

  1. Remove the timing bolt from the flywheel housing. Install the 8T-6765 Pipe Plug in the flywheel housing timing hole. Remove the engine turning pinion. Install the cover and the gasket.

  1. Be certain that the rocker arms are correctly engaged with the pushrods. Tighten the bolts in order to hold all of the rocker shafts in position.

  1. Make adjustments to the valves and to the unit injector lash. See Testing And Adjusting, "Valve Lash" and Testing And Adjusting, "Unit Injector Adjustment" for the correct procedures.

Fuel Timing


NOTICE

The camshafts must be correctly timed with the crankshaft before an adjustment of fuel timing is made. The timing pins must be removed from the camshafts before the crankshaft is turned or damage to the cylinder block will be the result.


Note: Refer to Testing And Adjusting, "Crankshaft Position for Unit Injector Adjustment and Valve Lash Setting" and put the engine in time. All of the injectors can be checked or adjusted with the crankshaft positions that are given in the chart. This check will make sure that the pushrod lifters are off the lobes and on the base circles of the camshafts.

Refer to the TMI (Technical Marketing Information) for the correct fuel timing dimension to use.

Table 4
Tools Needed    
5P-4160 Indicator Contact Point     1    
1U-8869 Dial Indicator     1    
9U-5138 Setting Gauge     1    
9U-5233 Magnetic Fixture Group     1    
9S-9082 Engine Turning Tool     1    



Illustration 12g00322956

1U-8869 Dial Indicator

  1. The digital dial indicator needs to be programmed to read actual timing dimensions. Since the 9U-5138 Setting Gauge in the timing and fuel setting tool group is 87.00 mm, the digital dial indicator is to be programmed for 87.00 mm. The following steps show how to program the indicator to read 87.00 mm.

    1. Turn the indicator ON by pushing the "on/off" button.

    1. Push the "in/mm" button so the display shows mm.

    1. A negative (-) sign should be in the display window under "REV". If that space is blank, push the "+/-" button so the display shows a negative (-) sign. When this is done, the movement of the plunger into the indicator will be displayed. The display will be shown as a negative movement. The movement of the plunger out of the indicator will be displayed as a positive movement.

    1. Push the preset button and hold the preset button down until there is a flashing "P" in the upper right corner of the display. Then release the button.

    1. Push the preset button and hold the preset button down until the flashing "P" disappears and a flashing indicator bar is seen in the lower left corner of the display. Then release the button. Momentarily pushing the preset button will cause a minus sign to appear or disappear above the flashing indicator. Use the preset button so that this position is blank.

    1. Push the preset button and hold the preset button down until the flashing indicator begins flashing under the first number position. The first number position is the fourth position to the left of the decimal. Then release the button. Momentarily pushing the preset will cause the display number in that position to change. Use the preset until this position reads zero (0).

    1. Use the preset button to move the flashing indicator and change the display numbers until the display shows 0087.00 mm. Push and hold the preset button until the flashing "P" is shown in the upper right corner of the display, and then release. Momentarily push the preset button so the flashing "P" and the zeroes to the left of 87.00 mm disappear.

    1. The indicator can now be turned off if desired. The indicator will retain the preset number in memory. To recall the preset number, repeat Steps 1.a through 1.d.

  1. Install a 5P-4160 Indicator Contact Point 19 mm (.75 inch) long, in the indicator stem.

  1. Install the indicator in the 9U-5233 Magnetic Fixture Group. Leave the collet loose.



    Illustration 13g00323023

    Adjustment Of Fuel Timing Tools

    (1) 1U-8869 Dial Indicator. (2) 9U-5233 Magnetic Fixture Group. (3) 9U-5138 Setting Gauge .

  1. Place the fixture and the indicator on the 9U-5138 Setting Gauge with the extension rod of the bracket on the step of the gauge. Position the indicator in the bracket so that the indicator plunger can travel adequately. Tighten the collet.

  1. Repeat Steps 1.a through 1.d.



    Illustration 14g00323029

    Fuel Timing Tools In Position

    (1) 1U-8869 Dial Indicator. (2) 9U-5233 Magnetic Fixture Group. (4) Injector follower. (5) Shoulder on injector body.

  1. Momentarily push the preset button on the digital dial indicator in order to stop the "P" in the upper right hand corner from flashing. The display should show 87.00 mm. Place the 1U-8869 Dial Indicator and the 9U-5233 Magnetic Fixture Group in position on the injector to be checked. Make sure that the magnetic base of the timing fixture is on the top surface of injector follower (4) and that the extension rod is on the top surface of injector shoulder (5) .

    Note: In order to ensure an accurate fuel timing dimension, make sure the top surfaces of the injector follower (4) and shoulder (5) are clean and dry.

  1. The digital dial indicator should now read the actual fuel timing dimension of the injector that is being checked.

  1. If the dial indicator reads the correct fuel timing dimension, as determined from the TMI (Technical Marketing Information) for the engine that is being checked, then no adjustment is necessary. Proceed to Step 12.

  1. If the dial indicator does not read the correct and/or desired fuel timing dimension, as determined from the TMI (Technical Marketing Information) for the engine that is being checked, do Steps 10 through 13.

  1. With the 1U-8869 Dial Indicator and the 9U-5233 Magnetic Fixture Group in position on the injector that is to be adjusted, loosen the push rod adjustment screw locknut for the injector that is to be adjusted.

  1. Turn the adjustment screw until the desired fuel timing dimension is read on the digital dial indicator.

    Note: Turning the adjustment screw clockwise will lower the fuel timing dimension. Turning the adjustment screw counterclockwise will increase the fuel timing dimension.

    Tighten the adjustment screw locknut to a torque of 70 ± 15 N·m (50 ± 11 lb ft) and check adjustment again. If necessary, repeat the procedure until the adjustment is correct.

  1. Remove the timing bolt from the flywheel when the fuel timing check is completed.

  1. Rotate the engine, repin the flywheel, and repeat the procedure for other half.

Injector Synchronization

Table 5
Tools Needed    
8T-2684 Rack Synchronization Gauge     1    

Injector synchronization is the setting of all injector racks to a reference position so each injector gives the same amount of fuel to each cylinder. Injector synchronization is done by setting each injector rack to the same position while the control linkage is in a fixed position. The procedure for the adjustment of injector synchronization follows.




Illustration 15g00323443

Location Of Fuel Setting Cover And Synchronizing Pin (Typical Example)

(1) Plug. (2) Synchronizing pin. (3) Cover.

  1. The top bolt that holds cover (3) in position is synchronizing pin (2). Remove synchronizing pin (2) and plug (1) from the front drive housing. DO NOT destroy the seal or remove cover (3) .

  1. Remove the washer from synchronizing pin (2) and install the washer into the threaded hole in the place that plug (1) was removed. Tighten synchronizing pin (2) .



    Illustration 16g00323444

    Synchronizing Position (Governor Fastener Cover Removed Only For Illustration) (Typical Example)

    (2) Synchronizing pin. (4) Fuel stop lever.

  1. Turn the governor or the actuator terminal shaft to the fuel "ON" position until the flat face of fuel stop lever (4) contacts synchronizing pin (2). This is the synchronizing position or zero reference point. Hold the control linkage in this position when the injectors are adjusted.

  1. Remove the valve covers.



    Illustration 17g00323446

    Location For Gauge And Control Rod Adjustment (Rocker Shaft Removed for Illustration) (Typical Example)

    (5) 8T-2684 Rack Synchronization Gauge. (6) Control rod.

  1. With the fuel stop lever against the synchronizing pin, put 8T-2684 Rack Synchronization Gauge (5) on the round part of the injector rack between the injector body and the end of the rack. Use a screwdriver and make an adjustment of control rod (6). Turn the screw on control rod (6) one click at a time until rack synchronizing gauge (5) just fits between the injector body and the shoulder at the end of the rack. Remove the screwdriver from control rod (6) so that no pressure is on the linkage while the setting is checked with rack synchronizing gauge (5). Any pressure on the linkage with the screwdriver will not give a correct indication when the setting is checked with the rack synchronizing gauge. In order to make sure that the linkage is free and that the linkage is giving the correct setting, move (flip) the linkage and check the setting again. Put the box end of a 9/16 inch combination wrench or a 5/8 inch combination wrench over the nut and the bolt that hold control rod (6) and the bellcrank together. Pull upward on the control rod two or three times and check the setting again.



    Illustration 18g00323448

    Gauge In Position On Injector Rack (Rocker Shaft Removed for Illustration) (Typical Example)

    (5) 8T-2684 Rack Synchronization Gauge. (7) Fuel injector rack.

  1. Use rack synchronizing gauge (5) and, if necessary, make the adjustment to the other injectors. When all adjustments have been made, release the actuator terminal shaft.



    Illustration 19g00323450

    Adjustment Of Fuel Control Rod (Typical Example)

    (5) 8T-2684 Rack Synchronization Gauge .

  1. Install the valve covers.

  1. Make a check of the fuel setting and make any necessary adjustments. Refer to Testing And Adjusting, "Fuel Setting" for this procedure.

Fuel Setting

Table 6
Tools Needed    
9U-5132 Engine Timing Tool Group     1    
4C-8753 Extended Collet     1    
6V-3075 Dial Indicator     1    
5P-7263 Indicator Contact Point     1    
8T-2684 Synchronization Gauge     1    

Refer to Special Instruction, SEHS9278 for the instructions on the use of the 4C-8753 Extended Collet .

Fuel Setting Check

Fuel setting is the adjustment of the fuel setting screw to a specified position. The fuel setting screw limits the power output of the engine by setting the maximum travel of all the injector racks.




Illustration 20g00323603

Synchronization And Fuel Setting Tools

(1) 8T-2684 Rack Synchronization Gauge Rack Synchronizing Gauge. (2) 6V-3075 Dial Indicator. (3) 4C-8753 Extended Collet. (4) 5P-7263 Indicator Contact Point .

Before the fuel setting is checked, the injectors must be correctly synchronized. Refer to Testing And Adjusting, "Injector Synchronization". After the injectors are synchronized correctly, leave the synchronizing pin in place for the procedure that follows.

  1. Put 6V-3075 Dial Indicator (2) with 5P-7263 Indicator Contact Point Contact Point (4) in 4C-8753 Extended Collet (3). Remove the plug from the right side of fuel setting cover (8) .



    Illustration 21g00323643

    Install The Dial Indicator (Typical Example)

    (2) 6V-3075 Dial Indicator with 5P-7263 Indicator Contact Point. (3) 4C-8753 Extended Collet .

  1. Move the governor or the actuator terminal shaft in the fuel "ON" direction until the flat face of fuel stop lever (6) contacts synchronizing pin (5). Hold the linkage in this position.



    Illustration 22g00323663

    Dial Indicator In Position (Cover Removed Only for Photo Illustration) (Typical Example)

    (2) 6V-3075 Dial Indicator. (4) 5P-7263 Indicator Contact Point. (5) Synchronizing pin. (6) Fuel stop lever.

  1. Install the dial indicator and collet (3) in the threaded hole. When the contact point seats against fuel stop lever (6), slide the dial indicator inward or outward until the indicator reads zero. Tighten collet (3) just enough to hold the indicator at this position.



    Illustration 23g00323683

    Checking Fuel Setting (Typical Example)

    (2) 6V-3075 Dial Indicator. (5) Synchronizing pin. (8) Fuel setting cover.

  1. Turn synchronizing pin (5) back out a minimum of 25 mm (1 inch) or remove it completely. Slowly move the governor or the actuator terminal shaft in the fuel "ON" direction until the flat face of the fuel stop lever is against the end of the fuel setting screw. With the linkage held in this position, the dial indicator reading will be the present fuel setting.

    Note: Refer to the TMI (Technical Marketing Information) for the correct fuel setting.

  1. If fuel setting is correct, remove the dial indicator and synchronizing pin (5). Install the two plugs, and install pin (5) back into cover (8) .

  1. If fuel setting needs adjustment, refer to Testing And Adjusting, "Fuel Setting Adjustment".

Fuel Setting Adjustment


NOTICE

A mechanic with governor and fuel setting training is the ONLY one to make adjustments to the engine fuel setting.


  1. Cut the seal wire and remove fuel setting cover (8) and the gasket. Loosen locknut (7). With the fuel stop lever still held against end of the fuel setting screw, turn the fuel setting screw inward or outward until the correct reading is on the dial indicator.



    Illustration 24g00323705

    Adjustment Of The Fuel Setting Screw (Typical Example)

  1. Now tighten locknut (7). Be sure that the fuel setting screw does not turn when the locknut (7) is tightened. Release the fuel linkage and move the linkage all the way in the fuel "ON" direction. Check the dial indicator reading again in order to be sure that the fuel setting is still correct.

  1. Remove the dial indicator and synchronizing pin (5). Install the two plugs.



    Illustration 25g00323706

    Install The Cover (Typical Example)

    (7) Locknut. (8) Fuel setting cover.

  1. Put fuel setting cover (8) and the gasket in position over the fuel setting screw. Install the bolt and synchronizing pin (5) in the cover. Install a new seal wire.

Engine Speed Measurement




Illustration 26g00286276

9U-7400 Multitach

The 9U-7400 Multitach can measure the engine speed from a tachometer drive. The tachometer drive is on the engine. The 9U-7400 Multitach also has the ability to measure engine speed from visual engine parts that are in rotation.

Special Instruction, SEHS7807 is with the 9U-7400 Multitach for the test procedure.

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