SERV1777January 2004

TECHNICAL PRESENTATION

DISTRIBUTOR-TYPE MECHANICALFUEL PUMP

3044C/3046C TIER II ENGINES

Meeting Guide 777

SERVICE TRAINING

DISTRIBUTOR-TYPE MECHANICALFUEL PUMP 3044C/3046 TIER II ENGINES

AUDIENCE

Level II - Service personnel who understand the principles of engine systems operation,diagnostic equipment, and procedures for testing and adjusting.

CONTENT

This presentation covers the distributor-type mechanical fuel pump used in the 3044C/3046engines for machine and industrial applications. This presentation describes the fuel injectionpump components and operation and covers in-chassis fuel system testing and adjustingprocedures.

OBJECTIVES

After learning the information in this presentation, the serviceman will be able to:

1. locate and identify the major components in the fuel injection pump;2. explain the function of the major components in the fuel injection pump;3. explain the operation of the fuel injection pump and governor; and4. perform in-chassis fuel system adjustments.

REFERENCES

3044C Engine Systems Operation, Testing and Adjusting Service Manual RENR75783044C Industrial Engines Operation and Maintenance Manual SEBU7578

Estimated Time: 1 HourIllustrations: 26Handouts: 3 Form: SERV1777Date: 1/04

© 2004 Caterpillar Inc.

TABLE OF CONTENTS

INTRODUCTION ........................................................................................................................5

FUEL SYSTEM............................................................................................................................7Fuel Injection Nozzles ..........................................................................................................10Fuel Injection Pump..............................................................................................................12Mechanical Governor Operation...........................................................................................22Timing Advance Mechanism................................................................................................27Fuel Pump Operation ............................................................................................................28In-chassis Fuel System Tests and Adjustments ....................................................................29Fuel Injection Timing............................................................................................................31Fuel Injection Pump Removal ..............................................................................................33

CONCLUSION...........................................................................................................................34

HYDRAULIC SCHEMATIC COLOR CODE...........................................................................35

VISUAL LIST ............................................................................................................................36

HANDOUTS...............................................................................................................................37

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NOTES

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INTRODUCTION

This presentation will discuss the distributor-type mechanical fuel pump used in the Caterpillar 3044C/3046C engines. Future Caterpillar engines may also be equipped with thisfuel pump.

The 3044C/3046C (Perkins 800 Series) engines provide power for machine and industrialapplications and are built by Mitsubishi Heavy Industries (MHI). These engines meet U.S.Environmental Protection Agency (EPA) Tier II Emissions Regulations for North America andStage II European Emissions Regulations.

NOTE: The 3044C-T engine was used for the out-of-chassis photos in this presentation.Components and systems may not be exactly the same for all applications using these engines.Refer to the appropriate machine service literature for the most accurate information.

1

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DISTRIBUTDISTRIBUTOR-TYPE MECHANICALOR-TYPE MECHANICALFUEL PUMPFUEL PUMP

3044C/3046C T3044C/3046C Tier II ENGINESier II ENGINES

© 2004 Caterpillar Inc.

2

The distributor-type fuel injection pump covered in this presentation is used on the enginesshown in the table above.

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DISTRIBUTOR-TYPE FUEL INJECTION PUMPENGINE APPLICATIONS

ENGINE APPLICATIONS

3044CT Skid Steer Loaders:236B/242B/246B/248B/252B/257B/262B/267B/268B/277B/287B

906/908 Compact Wheel Loaders

3046CT D3G/D4G/D5G Track-type Tractors

3044C and 3044CT

3054C Backhoe Loaders (Future)

Industrial

3

FUEL SYSTEM

The engine is equipped with an axial piston distributor injection pump that is mechanicallygoverned. The distributor-type injection pump delivers fuel to all cylinders through a singleaxially moving piston. The movement of the piston is parallel to the fuel injection pump driveshaft.

When the engine is cranking, the fuel is pulled from fuel tank through the primary fuelfilter/water separator by an electric fuel transfer pump. When the fuel passes through the waterseparator, the water flows to the bottom of the water separator bowl. From the fuel transferpump, the fuel flows through the fuel supply line to the fuel injection pump.

The injection pump distributes fuel through fuel delivery valves, located in the injection pumpdistributor head, and high pressure fuel lines to the fuel injection nozzles.

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InjectionPump

Distributor Head

Fuel Return Lines

FuelTank

Fuel TransferPump

�

Fuel Nozzles

�High Pressure Fuel Lines

Overflow Restrict ion

FuelSupply Line

Fuel Filter / Water Separator

FUEL SYSTEM

The fuel injection nozzles spray atomized fuel into the cylinder. Excess fuel from the nozzles isrouted through fuel return lines to the fuel tank. Excess fuel from the injection pump flowsthrough the overflow restriction to the tank, which provides cooling and venting for the injectionpump.

Routing excess fuel back to the fuel tank allows air in the fuel to flow back to the fuel tank. Thefuel that flows into the fuel injection pump housing lubricates and cools the internal componentsand removes small air bubbles.

The fuel injection pump requires fuel for lubrication to avoid damaging the precision parts in thepump. The engine must not be started until the fuel injection pump is full of fuel. The fuelsystem must be primed when any part of the fuel system is drained. Prime the fuel system whena fuel filter is changed, a fuel line is removed, or the fuel injection pump is replaced.

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4

This view shows the fuel system main components on a 3044C turbocharged engine in a "B" Series Skid Steer Loader:

- fuel injection pump (1)

- fuel nozzles (2)

- fuel filter/water separator (3)

- fuel transfer pump (4)

- fuel return line (5)

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5

21

4

3

5

Fuel Injection Nozzles

This illustration shows an indirect injection nozzle used in a naturally aspirated engine. Fuelunder high pressure enters the fuel inlet and flows to the bottom of the needle valve in thenozzle tip assembly. The fuel pressure pushes the needle valve against the spring. When thefuel pressure is greater than the spring force, the needle valve moves up.

When the needle valve opens, fuel under high pressure flows through the single orifice and intothe cylinder. The fuel is injected into the cylinder as a very fine spray. When the fuel is injectedinto the cylinder, the fuel pressure in the nozzle body decreases. When the spring force exceedsthe nozzle body fuel pressure, the needle valve moves to the closed position.

The seat of the needle valve has a close fit with the inside of the nozzle, which makes a positiveseal when the valve is closed.

When the fuel is injected into the cylinder, a small quantity of fuel will leak into the springchamber which lubricates the moving parts of the fuel injection nozzle. The excess fuel fromthe spring chamber flows through a passage in the fuel injection nozzle body and returns to thetank.

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Fuel Inlet

Body

Fuel Return

Retaining Nut Spring

Nozzle TipAssembly

FUEL INJECTION NOZZLENATURALLY ASPIRATED ENGINES

INDIRECT INJECTION

6

This illustration shows a direct injection nozzle used in a turbocharged engine. This nozzleoperates the same as the indirect injection nozzle previously described. The nozzle tip containsmultiple orifices rather than the one orifice used in the indirect injection nozzle.

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Fuel Inlet

Body

Retaining Nut

Fuel Return

Spring

Nozzle Tip

FUEL INJECTION NOZZLETURBOCHARGED ENGINES

DIRECT INJECTION

7

Fuel Injection Pump

This cutaway illustration of the distributor-type injection pump shows some of the majorcomponents. The distributor pump has only one high pressure pump chamber and one plungerregardless of the number of cylinders in the engine. The fuel is delivered through a groove inthe plunger to the outlet ports as determined by the number of cylinders in the engine.

The injection pump consists of the following subassemblies:

Feed pump: Consists of a vane-type pump that pulls fuel from the tank and supplies fuel to thehigh pressure pump chamber. The feed pump is driven by the pump drive shaft.

High pressure pump with distributor: Delivers fuel under high pressure through a plunger tothe delivery valves. The plunger moves axially due to the rotation of the cam plate. Theplunger is also driven by the pump drive shaft.

Mechanical governor: Controls engine speed through various load ranges. The flyweightscontrol the governor lever position.

Timing advance mechanism: Adjusts the start of fuel delivery as a function of pump speedand load.

Engine shutoff solenoid: When de-energized, blocks fuel to the plunger fill port to stop theengine.

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ControlLever

Flyweight

DriveShaft

Feed Pump

Roller Holder

Cam Plate

TimingAdvance

Mechanism Plunger Return Spring

Full-load AdjustingScrew

Governor Lever

Engine Shutoff Solenoid

Distributor Head

Plunger

Delivery Valve

Control Sleeve

FUEL INJECTION PUMP

High PressurePump Chamber

8

This view shows the injection pump on a 3044C engine. Components visible in this view of theinjection pump are:

- low idle adjustment screw (1)

- high idle adjustment screw (2)

- full load adjustment screw (3)

- speed control lever (4)

- engine shutoff solenoid (5)

- timing advance mechanism (6)

- distributor head (7)

- fuel inlet (8)

- timing control valve (9, if equipped)

The timing control valve prevents the engine timing from retarding when the engine loaddecreases if the temperature is below 60ºC (140ºF) or when the pump is used at high altitudes.

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3

2

4

5

7

9

1

6

8

9

The feed pump, located inside the pump housing, is driven by the pump drive shaft. The pumpdrive shaft is driven by the engine. The vane-type feed pump delivers fuel at a constant volumeper revolution regardless of pump speed. The fuel feed pressure is controlled by the pressureregulating valve that is located in the upper part of the feed pump. The fuel flows into theinjection pump chamber through a delivery port in the feed pump cover.

The cam plate is also driven by the drive shaft. The cam plate rides on the rollers of the rollerholder, which is located between the cam plate and the feed pump. The position of the rollerholder is determined by the position of the timing advance mechanism. The position of thetiming advance mechanism is determined by the feed pump pressure acting on the timer piston,which is used to advance the injection timing.

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Idling Spring

Full-load Adjusting Screw

Tension Lever

Governor Lever Assembly

Plunger

Plunger Barrel

Delivery Valve

Control Sleeve

Plunger Return Spring

Cam Plate

Roller Holder RollerTimer PistonCross Coupling

Driving Gear

Feed PumpDrive Shaft

Regulating Valve

Control Lever Shaft

Control Lever Flyweight

Governor Spring

Engine Shutoff Solenoid

INJECTION PUMPCOMPONENTS

From Transfer Pump

Orifice

To Tank

The distributor plunger and the cam plate are held against the roller holder by the distributorplunger return springs. As the cam plate and the distributor plunger rotate, they also move backand forth over the rollers an amount equal to the height of the cam lobes. The distributorplunger moves inside the distributor head, which is attached to the pump housing. The motionof the plunger, within the distributor head, delivers fuel under high pressure to the combustionchamber of each cylinder through delivery valves, high pressure lines, and injector nozzles.

The quantity of high pressure fuel delivered to each cylinder is determined by the position of thecontrol sleeve on the plunger. The governor controls the position of the control sleeve throughthe flyweights and governor lever assembly. A gear attached to the pump drive shaft spins thecentrifugal flyweight assembly.

With the ignition switch in the OFF position, the engine shutoff solenoid is de-energized andfuel flow to the plunger barrel is blocked. The engine shutoff solenoid is located on the top ofthe distributor head.

NOTE: To crank the engine without starting, remove one of the engine shutoff solenoid wires.

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10

The vane-type feed pump, located inside the injection pump, draws fuel from the tank throughthe fuel filter/water separator and transfer pump and supplies it to the pump housing.

The feed pump rotor is connected to the drive shaft by a woodruff key, and is driven by thepump drive shaft. As the rotor spins, centrifugal force holds the vanes against the wall of theconcentric ring (pressure chamber) that is held stationary against the pump housing. Due to theoff-center location of the concentric ring, with respect to the rotor, fuel becomes trappedbetween the vanes and is pressurized and forced out through the delivery port in the feed pumpcover and into the pump housing.

The pressure regulating valve is located in the upper portion of the injection pump housing onthe drive end. The pressure regulating valve controls fuel pressure within the pump housing,proportional to pump speed.

As fuel pressure increases with pump speed, the piston within the pressure regulator valve isforced against the tension of the regulator spring. Fuel flows through a port in the regulatorallowing excess fuel to return to the intake port and keeping the fuel pressure proportional topump speed. This fuel pressure is also used to actuate the timing advance mechanism by actingdirectly against the timer piston.

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Regulating Valve

FromFuel TankKey

PressureChamber

Drive shaft Rotor Blade

To PumpHousing

From TimingAdvance UnitSpring Cavity

FEED PUMP

11

The drive shaft drives the feed pump, the cam plate, and the plunger simultaneously. Plungerback and forth movement is accomplished through the movement of the cam lobes over theroller holder assembly rollers. When the plunger inlet slot and the inlet port of the plungerbarrel align, fuel enters the pressure chamber.

After the plunger barrel inlet port has been closed from the rotation of the plunger, the cam lobemoves the plunger to the right and increases fuel pressure. When the plunger outlet slot and theplunger barrel outlet port align and the fuel pressure exceeds the delivery valve spring force, thedelivery valve opens and fuel flows to the injection nozzle.

When the plunger spill port is not blocked by the control sleeve end face, fuel is allowed to flowinto the injection pump housing and fuel delivery is completed.

The plunger barrel has only one inlet port, but has an outlet port for each engine cylinder.However, although the plunger has the same number of inlet slots as engine cylinders, it hasonly one outlet slot.

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Plunger

Plunger Barrel

Delivery Valve

ControlSleeve

PlungerReturn Spring

Cam PlateRoller

INJECTION PUMPPLUNGER OPERATION / INTAKE STROKE

Feed Pump

DriveShaft Gear

RollerHolder

SpillPort

Inlet Slot

To InjectionNozzle

OutletSlot

Inlet Port

Pressure Chamber

Engine Shutoff Solenoid

12

During the injection pump intake stroke, the plunger moves left and fuel from the feed pumpfills the pressure chamber between the plunger and plunger barrel. At the same time, theplunger rotates to align the plunger inlet slot with the intake port in the distributor head.

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Plunger

Pressure Chamber

Delivery Valve

Engine Shutoff Solenoid

Plunger Spring

INJECTION PUMPINTAKE STROKE

Intake PortInlet Slot

Delivery Spring

13

During the injection stroke, as the plunger rotates, the intake port is closed and fuel becomestrapped within the pressure chamber. The plunger moves to the right, caused by the cam lobeacting on the roller, and fuel pressure increases. As the outlet port aligns with a passage in thedistributor head, fuel is directed to the delivery valve.

The delivery valve opens and pressurized fuel is sent to the injection nozzle.

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Outlet Slot

Outlet Port

INJECTION PUMPINJECTION STROKE

To InjectionNozzle

14

Injection continues as the plunger moves farther to the right until the plunger spill port is beyondthe end of the control sleeve. Fuel in the plunger chamber returns to the pump housing throughthe spill port. Pressure in the plunger chamber decreases and spring force closes the deliveryvalve.

When the delivery valve closes, the fuel between the injector nozzle and delivery valve isblocked.

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Control Sleeve

Spill Port

INJECTION PUMPEND OF INJECTION

To InjectionNozzle

15

When the ignition switch is turned to the START position (left view), the engine shutoffsolenoid is energized and the solenoid valve lifts against spring force and opens the inlet port tothe plunger pressure chamber. After the engine has started and the ignition switch is in the ONposition, the current flows through a resistor to the solenoid. The current is reduced butmaintains enough energy to hold the valve open.

Turning the ignition switch to the OFF position (right view) shuts off the current to the solenoid.With no current to hold the valve open, spring force closes the valve. The fuel passage isblocked, which shuts off the fuel supply and stops the engine.

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Fuel Passage

DURING OPERATION

Solenoid Valve

Spring

Armature

Inlet Port

SHUTOFF

ENGINE SHUTOFF SOLENOID

16

Mechanical Governor Operation

The mechanical governor automatically controls the engine speed and output by adjusting thefuel injection quantity according to the load on the engine, the distance the accelerator pedal isdepressed, and the position of the governor lever assembly. The governor moves the controlsleeve in the pump to change the effective stroke of the pump plunger and then controls theinjection quantity regardless of the position of the control (throttle) lever.

The plunger stroke remains constant while the control sleeve position is controlled by thegovernor. For less fuel, the effective stroke is reduced by moving the control sleeve away fromthe plunger barrel, thus allowing the trapped fuel pressure to release sooner. For increased fuel,moving the control sleeve closer to the plunger barrel keeps the fuel pressure trapped longer, andincreases the effective stroke.

The injection volume is controlled by the centrifugal force of the flyweights generated by therotation of the pump drive shaft. The injection volume is controlled very accurately at highspeeds, but less accurately at low speeds.

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Corrector Lever

Governor LeverAssembly

ControlSleeve

BallJoint

Drive Shaft

Gear

Control Lever

FlyweightGovernor Spring

INJECTION PUMPGOVERNOR COMPONENTS

Gear

Governor Sleeve

Starting Lever

Tensioning Lever

Fulcrum

Starting Spring

Decreasing Injection Quantity Increasing Injection Quantity

Longer Effective Stroke

Shorter Effective Stroke

The governor is located in the top section of the injection pump and includes the centrifugalflyweights, governor lever assembly, governor spring, and control lever.

The flyweight assembly, located on the governor shaft, is rotated approximately 1.6 times thespeed of the pump drive shaft and is driven by a gear on the drive shaft and a gear on theflyweight assembly. As the drive shaft rotates it spins the flyweight assembly causing theflyweights to move outward.

The four flyweights move against the thrust washer and the governor sleeve on the governorshaft. The governor sleeve acts on the governor lever assembly. The governor lever assemblyconsists of the corrector lever, tensioning lever, starting lever, starting spring, and the ball joint.

Before the engine is started, the starting lever is separated from the tensioning lever by thestarting spring. The starting lever moves the governor sleeve to close the flyweights. The balljoint, at the bottom of the starting lever, pivots at the fulcrum and moves the control sleeve tothe FUEL ON position for engine starting.

After the engine has started, the centrifugal force of the flyweights overcomes the force of thegovernor spring, moving the control sleeve back to the position where the force on theflyweights is balanced with the tension of the governor spring.

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17

Once the engine has started, the control lever (not visible) is returned to the idle position. Thecontrol lever is attached to the control lever shaft. With little or no tension on the governorspring, the centrifugal force of flyweight is counterbalanced by the force of the idling spring.

The control sleeve moves left, to a position where the forces on the flyweights and springs arebalanced, maintaining the desired idling speed.

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Flyweight

Corrector Lever

Tension Lever

Governor Spring

Plunger

Start ing Lever

Pivot Bolt (Fixed)

Control Sleeve

Governor Sleeve

Fulcrum

Idling Spring

GOVERNOR OPERATIONIDLING

Effect ive Stroke

Control Lever Shaft

18

When the throttle lever is moved to the HIGH IDLE position from LOW IDLE with no load onthe engine, governor spring tension increases and initially moves the tension lever left. Thetension lever and starting lever move the governor sleeve to the left. The ball joint, at thebottom of the starting lever, pivots at the fulcrum and moves the control sleeve to the rightwhich increases the plunger effective stroke and increases fuel flow to the fuel nozzles.

As the engine starts to overspeed, the centrifugal force of the flyweights causes the flyweights tomove out. As the flyweights move out, flyweight force overcomes the tension of the governorspring. The governor sleeve moves back to the right, contacting and moving the starting leverand tension lever to the right. The ball joint pivots at the M2 fulcrum and moves the controlsleeve to the left. The control sleeve allows fuel to flow out the spill port which decreases fuelto the nozzles.

The control sleeve will continue to move to the left until the governor spring and the flyweightsreach the equilibrium point. At this point, the governor is in the NO LOAD MAXIMUMSPEED condition or at HIGH IDLE.

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Flyweight

Idling SpringGovernor Spring

Spill Port

Governor Sleeve

Start ing Lever

Pivot Bolt (Fixed)

Control Sleeve

Tension Lever

Corrector lever

Fulcrum

Full-loadAdjust ing

Screw

GOVERNOR OPERATIONHIGH IDLE

Control Lever Shaft

19

As the load on the engine increases, the rotating speed of the flyweights is reduced. Thegovernor spring, idling spring, and tension lever overcome the flyweight force and move thegovernor sleeve to the right to increase fuel flow. The increase in fuel flow results in higherengine torque at the lower engine speed.

The tension lever travel is limited by the pin, which is attached to the pump housing. The fullload fuel injection quantity can be adjusted with the full load adjustment screw. Turning theadjustment screw in will increase the fuel setting and turning the screw out will decrease the fuelsetting.

NOTE: The full load adjustment should only be performed on the fuel test bench by a qualifiedtechnician. The full load adjustment should never be performed in-chassis.

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Flyweight

Idling SpringGovernor Spring

Corrector Lever

Full-loadAdjust ing Screw

Start ing Lever

Control Sleeve

Fulcrum

GOVERNOR OPERATIONFULL LOAD

Pivot Bolt (Fixed)

Tension Lever

Effect ive Stroke

Governor Sleeve

Control Lever Shaft

20

Timing Advance Mechanism

The timing advance mechanism is located in the lower part of the pump housing and movesback and forth during engine operation to control timing advance.

When static, the timer piston is held against the timer cover plate by the tension of the timerspring (left view).

As engine speed increases, fuel feed pump speed increases and injection pump internal pressureincreases. Fuel under pressure moves the timer piston against timer spring force (right view).The timer piston moves the slide pin. The slide pin links the roller holder and the timer piston.The roller holder pivots in the opposite direction of the injector pump rotation. When the rollerholder pivots, the cam lobes contact the rollers sooner and injection timing is advanced.

Since fuel feed pressure is proportional to pump speed, timer movement is also proportional topump speed.

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Timer Piston

Roller

Roller HolderAssembly

Drive Shaft

Timer Spring Slide Pin Low PressureChamber

High PressureChamber

TIMING ADVANCE MECHANISM

To FeedPump Inlet

Timer CoverPlate

21

Fuel Pump Operation

This illustration shows all the internal pump components during the injection stroke.

As previously discussed, the feed pump delivers fuel at a constant volume to the pump housing.As the cam plate and distributor plunger rotate, they move over the rollers and the fuel ispressurized. As the outlet port aligns with a passage in the distributor head, fuel is directed tothe delivery valve.

The delivery valve opens and pressurized fuel is sent to the injection nozzle.

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Idling Spring

Full-load Adjusting Screw

Tension Lever

Governor Lever Assembly

Plunger

Plunger Barrel

Delivery Valve

Control Sleeve

Plunger Return Spring

Cam Plate

Roller Holder RollerTimer Piston

Cross Coupling

Driving Gear

Feed PumpDrive Shaft

Regulating Valve

Control Lever Shaft

Control Lever Flyweight

Governor Spring

Engine Shutoff Solenoid

From Transfer Pump

To Injection Nozzle

INJECTION PUMPCOMPONENTS

22

In-chassis Fuel System Tests and Adjustments

HIGH and LOW IDLE can be checked in-chassis. LOW IDLE may be adjusted in-chassis,while HIGH IDLE should only be adjusted on a test bench. The most accurate way to correctlytest and adjust the pump and governor is on the test bench.

The high idle (1) and low idle (2) screws adjust maximum and minimum engine speed. The fullload adjustment screw (3) limits the plunger effective stroke during FULL LOAD conditions.

Maximum horsepower is achieved when the tension lever contacts the full load stop pin (withthe engine at FULL LOAD rpm). A misadjusted full load adjustment screw can cause theengine horsepower to be out of specification. FULL LOAD rpm cannot be adjusted in-chassis.

If the engine has a power problem, other areas to check include: the fuel grade and quality,external linkage, altitude deration, plugged air and fuel filters, air in the fuel lines, fuel nozzles,and injection timing.

NOTE: The adjustment screws for HIGH IDLE and FULL LOAD are sealed at the factory toprevent tampering. HIGH IDLE will vary from one machine to another due to parasitic loads ordue to slight differences in the governor spring. As with other Caterpillar engines, the FULLLOAD rpm is critical. FULL LOAD rpm cannot be adjusted in-chassis. Attempting to adjustHIGH IDLE in-chassis may result in the FULL LOAD rpm being out of specification, whichcan affect engine performance.

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1

2

3

23

If engine performance is low, a malfunctioning fuel injection nozzle may be the cause. To test afuel injection nozzle in-chassis, operate the engine at LOW IDLE and check the engine speed.After recording the LOW IDLE rpm, loosen the connection at the fuel supply line (1) to thesuspected injector. Do not bend the metal fuel line. With the fuel supply line loose, operate theengine again at LOW IDLE and check the engine rpm.

If the engine speed decreases from the previous LOW IDLE measurement, the performanceproblem is probably not related to that injector. If the low idle speed remains the same as beforedisconnecting the fuel supply line, remove the injector and test it on a nozzle test stand. If theinjector is defective, either repair or replace it. Then, recheck the engine performance.

To remove a fuel injection nozzle, loosen the fuel return line (2) from each injector and removethe return line. Remove the high pressure fuel injection line. Loosen the bolt (3) and removethe clamp. The injector should pull straight out of the head. If the injector does not slide out ofthe head easily, use a wrench to turn the injector while pulling the injector out.

NOTE: Cylinder compression can also be checked by removing the fuel injection nozzle andinstalling a compression pressure gauge, hose, and the proper fitting.

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2

1

3

24

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Fuel Injection Timing

Incorrect fuel injection timing can cause poor engine performance. The fuel pump drive shaftdrives the cam plate. Rotating the fuel pump relative to the cam plate changes fuel injectiontiming.

To check timing, the No. 1 cylinder must be at Top Center (TC). Remove the valve cover androtate the engine in the normal direction of engine rotation until the inlet valve of the No. 4cylinder has just opened and the exhaust valve of the No. 4 cylinder has not completely closed.

Align the TC mark (1) on the crankshaft pulley with the pointer (2) on the timing case.

Remove the bolt (3) from the port plug (4) in the distributor head and install dial indicator 192-3331 (5). Set a preload on the dial indicator of approximately 10 mm (0.4 in.). The dialindicator measures the cam lift at the end of the plunger while manually rotating the engine.Rotate the crankshaft in the opposite direction of engine rotation until the reading on the dialindicator stabilizes indicating the bottom of plunger lift. Set the dial indicator to zero.

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5

6

2

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7

8

Rotate the crankshaft in the normal direction of engine rotation until the 5º mark (6) on thecrankshaft pulley is aligned with the pointer on the timing case. The dial indicator readingshould be 0.5 mm (0.020 in.).

If the dial indicator reading is not 0.5 mm (0.020 in.) with the crankshaft pulley at the 5º mark,adjust the timing by rotating the pump. The pump flange bolt holes are slotted so the pump canbe rotated.

Loosen the flange nuts and the nut (7) securing the pump head to a bracket on the engine block.The outboard flange nut (8) is visible in this view. Rotate the pump while observing the dialindicator to obtain a reading of 0.5 mm (0.020 in.) and then tighten the nuts.

NOTE: The injections lines have been removed in this view for clarity. The injection linesmay not need to be removed to install the dial indicator.

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Fuel Injection Pump Removal

The injection pump and pump drive gear can be removed as a unit. If the pump drive gear (1)must be removed from the pump, remove the nut (2) on the end of the pump drive shaft. Loosenthe pump drive gear from the pump drive shaft while the pump is secured in the engine to aid inremoval. Using the appropriate puller, loosen the pump drive gear from the pump drive shaft.

Remove the fuel lines (3), fuel return line bolt (4), and the nut (5) securing the pump head to abracket on the engine block. Loosen the pump flange nuts (6) and remove the the pump housingbolts (7). Four of the pump housing bolts are visible in the bottom right view.

Remove the pump and pump drive gear together. If necessary, remove the nut on the end of thepump drive gear and remove the gear from the pump drive shaft.

NOTE: Ensure the pump drive gear teeth are properly aligned with the idler gear teeth duringthe installation procedure, by using the reference marks (8) on the gear teeth. If the marks arenot visible, mark the teeth before removal to ensure correct alignment upon installation.

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2

2

3

4

567

7

8

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CONCLUSION

This presentation has provided information for the distributor-type mechanical fuel injectionpump on the 3044C/3046C engines and future 3054C engines. When used in conjunction withthe Service Manual, the information in this package should permit the technician to analyzeproblems in the fuel injection system on these engines.

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HYDRAULIC SCHEMATIC COLOR CODE

This illustration identifies the meanings of the colors used in the hydraulic schematics and cross-sectional views shown throughout this presentation.

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Dark Gray - Cutaway section

Light Gray - Surface color

Red - High pressure oil

Red/White Stripes - 1st pressure reduction

Red Crosshatch - 2nd reduction in pressure

Pink - 3rd reduction in pressure

Red/Pink Stripes - Secondary source oil pressure

Orange - Pilot, signal, or Torque Converter oil

Orange/White Stripes -Reduced pilot, signal, or TC oil pressure

Green - Tank, sump, or return oil Blue - Trapped oil

Brown - Lubricating oil

Purple - Pneumatic pressure

Orange Crosshatch - 2nd reduction inpilot, signal, or TC oil pressure.

White - Atmosphere orAir (no pressure)

Yellow - Moving or activated components

Cat Yellow - (restricted usage)Identification of componentswithin a moving group

Black - Mechanical connection. Seal

Green/White Stripes -Scavenge Oil or Hydraulic Void

HYDRAULIC SCHEMATIC COLOR CODE

STMG 777 - 36 -1/04

1. Fuel injection pump2. Fuel pump engine applications3. Fuel system block diagram4. Fuel system components5. Indirect injection nozzle6. Direct injection nozzle7. Fuel injection pump cutaway8. Fuel injection pump components9. Injection pump sectional view

10. Feed pump11. Injection pump--Plunger operation12. Injection pump--Intake stroke13. Injection pump--Injection stroke

14. Injection pump--End of injection15. Engine shutoff solenoid16. Mechanical governor17. Governor--Idle position18. Governor--High idle19. Governor--Full load20. Timing advance mechanism21. Fuel pump adjustment screws22. Fuel nozzle23. Fuel injection timing24. Injection pump removal25. Fuel injection pump

ILLUSTRATION LIST

Da

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STMG 777 - 37 - Handout No. 11/04

2

INJE

CT

ION

PU

MP

1 3 4

56

789

10

111213

141516

STMG 777 - 38 - Handout No. 21/04

Fue

l Inj

ecti

on P

ump

Che

cklis

t

Dir

ecti

ons:

Fill

in th

e bl

anks

with

the

corr

ect r

espo

nse.

U

se th

is s

heet

to ta

ke n

otes

dur

ing

the

pres

enta

tion.

Iden

tify

Com

pone

nts

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

TEST SPECS ACTUAL COMMENTS

High Idle

Low Idle

Full Load Engine rpm

Fuel Injection Timing:

Valve Clearance

Cylinder Compression: No. 1

No. 2

No. 3

No. 4

Plunger Lift

Timing Mark

Engine rpm:

No. 5

No. 6

STMG 777 - 39 - Handout No. 31/04

Engine In-Chassis Test Sheet

Machine Model Dealer

Name/Code Customer

Machine S/N Job

Engine S/N Date

S.M.H. Technician

VISUAL CHECKS: Fuel Level Engine Oil level

Coolant level Hydraulic Oil level

Oil/Coolant/Fuel Leaks Air Filter and Precleaner Inspection

STMG 777 - 40 - Handout No. 41/04

1. The injection pump distributes fuel through fuel delivery valves, located in the injectionpump distributor head, and high pressure fuel lines to the fuel injection nozzles.

a. Trueb. False

2. Plunger back and forth movement is accomplished through the rotation of the pump drive shaft.

a. Trueb. False

3. The governor changes the length of the plunger stroke to control the injection quantity.

a. Trueb. False

4. The fuel pump is rotated relative to the cam plate to change fuel injection timing.

a. Trueb. False

5. How many high pressure pump chambers and plungers are in the distributor pump.

a. Oneb. Twoc. Fourd. Depends on the number of cylinders in the engine

II. Circle the best answer.

6. The fuel feed pressure is controlled by the __________________________________.

a. transfer pumpb. shutoff solenoidc. pressure regulating valved. timer piston

7. When the ignition switch is turned to the START position, the engine shutoff solenoid is:

a. energizedb. de-energized

Distributor-type Mechanical Fuel Pump Posttest

I. Modified True/False: If the question is false, circle the word or words that make thestatement incorrecct and replace with the words(s) to make the statement correct.

Posttest Answers

I. Modified True/False: If the question is false, circle the word or words that make thestatement incorrecct and replace with the words(s) to make the statement correct.

1. a. True2. b. False. Replace rotation of the pump drive shaft with movement of the cam lobes

over the roller holder assembly roller3. b. False. Replace changes the length of the plunger stroke with moves the control

sleeve in the pump to change the effective stroke of the pump plunger4. a. True5. a. True

II. Circle the best answer.

6. c. pressure regulating valve7. a. energized

STMG 777 - 41 - Handout No. 51/04