In this article, we will consider the removal, check and installation of elements of the engine fuel system.

Replacement of injection pump

Disconnect the negative terminal of the battery

Замена элементов топливной системы Cummins ISF3.8

Disconnect the inlet and outlet tubes from the injection pump

Disconnect the fuel supply line leading to the rail from the high-pressure pump and loosen the fastening of the support brackets.

Disconnect the fuel control valve harness connector

Замена элементов топливной системы Cummins ISF3.8

Unscrew the three bolts securing the high pressure fuel pump

Remove the fuel pump from the crankcase of the timing gears

Disassembly

Disassembly involves only replacement of the pump drive.

Use the Fuel Pump Gear Replacement Tool (# 4919109) and 1/2 "pry bar to hold the fuel pump drive gear in place.

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Loosen the fuel pump drive gear retaining nut by turning it counterclockwise.

Do not remove it from the shaft.

Install Snap-On TM Bearing Remover (P / N CJ951) between the fuel pump mounting flange and the drive gear.

Lock the bearing remover.

Install the Snap-On TM Puller (# CG150) onto the Snap-On TM Bearing Remover (# CJ951) and the fuel pump drive shaft.

Замена элементов топливной системы Cummins ISF3.8

Rotate the puller screw to separate the gear from the drive shaft.

Remove the fuel pump drive gear retaining nut, lock washer and gear from the fuel pump drive shaft.

Assembly

Before reassembling, clean and dry the nose of the drive shaft and the seating surface of the pinion gear.

Wipe the drive shaft and gear with a lint-free cloth and solvent.

Do not touch the seating surfaces after wiping.

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Install the drive gear on the drive shaft, the lock washer and hand tighten the gear nut.

Using a puller, hold the gear against turning, tighten the nut of its fastening. Tightening torque 105 Nm

Installation

Note: Synchronization of the fuel pump with the crankshaft is not required.

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Install the fuel pump to the timing gear housing.

Install the fuel pump mounting bolts. Tightening torque 25 Nm

Install the high pressure fuel pipe from the injection pump to the fuel rail, tighten the clips.

Note: hold the high pressure pump outlet with a second wrench to prevent over tightening. Tightening torque 21 ± 4 Nm

Connect the flow control valve harness connector.

Install the fuel pipes.

Install drain tubes.

Connect the wires to the battery terminals.

Fill the system with fuel.

Checking and replacing the fuel control valve

Проверка и замена клапана управления подачей топлива

We measure the resistance of the fuel control valve.

The maximum resistance should be 5 ohms

Removing the valve

Disconnect the connector

Unscrew the three bolts

Remove the feed control valve by turning and pulling it out

Проверка и замена клапана управления подачей топлива

Installation

Install a new O-ring on the fuel control valve. Lubricate the new O-ring with clean oil.

We install the fuel control valve by turning it and inserting it inside flush with the landing surface of the injection pump.

Torque:

- the first stage 3 Nm;

- second stage 7 Nm.

We connect the connector.

Injectors

Fuel drain check

Note: Defective injectors will cause excessive fuel leakage from the return line.

For engines with a fuel rail pressure relief valve quick disconnect, use an appropriate drain hose and plug to block fuel flow through the pressure relief valve.

Disconnect the quick release connector from the pressure relief valve.

Connect the pressure gauge adapter (# 4918462) to the fuel accumulator pressure relief valve and drain the fuel into a container.

Install a quick release plug (# 4918464) on the fuel return hose to prevent fuel from entering the fuel return line.

Start the engine. Switch on the "Fuel Leakade Test" mode on the "INSITE" diagnostic complex and let the operating temperature rise for 1 minute. At elevated temperatures, greater measurement accuracy is achieved.

Place the drain hose (no. 4918462) in a measuring container and measure the amount of fuel drained in 1 minute. The "Fuel Leakade Test" mode of the "INSITE" diagnostic complex is switched on less than 200 ml / minute

Idling (no leaks) less than 120 ml / minute

Engine cranking less than 90 ml / minute

If the fuel leaks are greater than the maximum value, it is necessary to block the return of fuel at one of the injectors in order to localize the cause of the excessive leaks.

With the engine stopped, remove the high pressure fuel pipe of the first cylinder.

Замена элементов топливной системы Cummins ISF3.8

Install a plug (# 4918860) on the fuel accumulator fitting where the high pressure fuel line of the first injector is attached. Tightening torque 30 Nm

Repeat the leak check and record the result.

Install the high pressure fuel pipe

Repeat the leak check one at a time, shutting off the remaining injectors.

Замена элементов топливной системы Cummins ISF3.8

Determine which of the injectors is leaking (if the faulty injector is blocked, leaks are minimal). If the leaks are approximately equal, then several injectors may be damaged.

Withdrawal

Disconnect the connectors from the injectors.

Disconnect the high pressure fuel pipes from the injectors and from the fuel rail.

Note: clean all connections before disassembling. Ingress of dirt or debris can damage the fuel system.

Remove the nut and disconnect the # 4 high pressure fuel pipe from the fuel accumulator.

Remove the nut and disconnect the # 4 high pressure fuel pipe from the # 4 injector.

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Repeat the procedure for the rest of the injectors. Cover all open ports with caps.

Remove the cylinder head cover.

Remove the injector drain line.

Note: mark the installation locations of all fuel drain pipe holders and gaskets so that they are installed in the locations from which they were removed during reassembly.

Remove the injectors.

Unscrew the nuts securing the injector wiring, remove the wires.

Loosen and remove the injector holder bolt. c) a pry bar with a small heel can be used to remove the nozzle. Lift the injector using the retaining flange (the part of the injector body just above the cylinder head casting).

Remove the nozzle holder.

Remove the injector from the cylinder head.

Examination

Clean the nozzle in an ultrasonic bath with aqueous solution.

Check the condition of the nozzle parts for damage.

Place the protective cap over the injector nozzle.

Замена элементов топливной системы Cummins ISF3.8

Note: As a result of overheating, the atomizer turns brownish-yellow or blue, causing damage to the injector, depending on the degree of overheating.

Check the resistance at the injector leads.

Rated impedance less than 3 ohms

Installation

Check the thickness of the new copper sealing washer.

Nominal thickness 2.5 mm

Do not use two copper washers!

Remove dirt around the nozzle bore.

Lubricate the injector O-ring with engine oil.

If the injector is working properly, install it in the place from where it was removed.

Install the holder onto the nozzle before installing the nozzle into the bore.

Correctly orient the injector in the cylinder head (fuel connection towards the high pressure fuel pipe connector).

Use the transport cap on the top of the nozzle to ensure that it is seated correctly.

Install the injector holder mounting bolt.

Install the 3 remaining nozzles.

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Install the cylinder head cover without seals. Tighten one screw on each side of the cover.

Connect the high pressure fuel pipe to the injector. Using the tube nut as a guide, center the nozzle in the seal.

Remove the high pressure fuel pipe from the injector and repeat for the rest of the injectors.

Замена элементов топливной системы Cummins ISF3.8

Remove the cylinder head cover.

Tighten the injector holder bolts evenly in several passes.

Note: Tighten the bolts one at a time, turning 90 °, until the rated torque is reached. Tightening torque 33 Nm

Замена элементов топливной системы Cummins ISF3.8

Connect the injector wires and tighten the nuts.

Tighten the nuts.

Note: Route the injector wires so that they do not come into contact with each other or with the rocker arms.

If the rocker arm comes in contact with the injector wiring, the wiring insulation will be damaged, causing diagnostic codes to appear. Tightening torque 1.5 Nm

Install the cylinder head cover.

Connect the high pressure fuel pipes.

Loosen the fuel rail mounting bolts. Do not remove the fuel rail! Bolts are loosened to ensure correct orientation of the fuel rail after the high pressure fuel pipes are installed.

Замена элементов топливной системы Cummins ISF3.8

Install and hand tighten the high pressure fuel pipe retaining nuts.

Tighten the high pressure fuel pipe retaining nuts. Tightening torque 22 Nm

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Tighten the fuel rail mounting bolts. Tightening torque 24 Nm

Connect the wires to the battery.

Start the engine and check for leaks.

Removal and installation of the fuel rail

Disconnect the negative terminal of the battery

Remove the high pressure fuel pipes.

Remove the nut and disconnect the # 4 high pressure fuel pipe from the fuel accumulator.

Remove the nut and disconnect the # 4 high pressure fuel pipe from the # 4 injector.

Repeat the procedure for the rest of the injectors. Cover all open ports with caps.

Замена элементов топливной системы Cummins ISF3.8

Disconnect the fuel pressure sensor connector. Note: do not remove the fuel pressure sensor as it will require replacement if removed.

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Remove the fuel return line from the fuel pressure reducing valve.

Disconnect the high pressure fuel pipe connecting the injection pump and the fuel rail from the fuel rail.

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Remove the fuel rail mounting bolts.

Remove the fuel rail.

Installation

Install the fuel rail.

Install the fuel rail to the engine.

Tighten the fuel rail mounting bolts by hand.

Connect the high pressure fuel line from the injection pump to the fuel accumulator.

Note: keep the union from turning. Tightening torque 30 Nm

Замена элементов топливной системы Cummins ISF3.8Замена элементов топливной системы Cummins ISF3.8

Install the high pressure fuel pipes to the injectors and the fuel rail.

Tighten the fuel rail mounting bolts. Tightening torque 24 Nm

Connect the fuel pressure sensor connector.

If removed, install the fuel pressure sensor. Tightening torque 70 Nm

Connect the fuel return line to the fuel pressure reducing valve.

If removed, install a pressure reducing valve. Tightening torque 100 Nm

Connect the wires to the battery.

Start the engine and check for leaks.

Pressure reducing valve

Examination

Remove the quick connector from the relief valve and replace the pressure gauge adapter (# 4918462).

Install the quick disconnect plug (# 4918464) on the return line disconnected from the pressure relief valve.

Place the end of the drain hose in a measuring container.

Turn on the fuel system pressure check in the "INSITE TM" diagnostic system or let the engine idle.

Place the other end of the drain hose or pressure gauge adapter into a container and measure the flow.

Idle specifications: No flow

When the check of the "INSITE tm" diagnostic complex is turned on: Maximum fuel consumption 16 ml per minute.

Note:

- If too much fuel comes out of the pressure relief valve, restart the engine and set a high idle speed.

The engine management system will attempt to use the valve to correct the problem.

- If trouble codes 449, 1911, 2311, 272, 553 or 2216 appear, do not replace the pressure reducing valve until the cause of the failure is determined.

Removal and installation

Unscrew the pressure relief valve.

Clean the contact surfaces from dirt.

Screw on the pressure relief valve. Tightening torque 100 Nm

Fuel filter

Removal and installation

Disconnect the connector from the water sensor.

Loosen and remove the fuel filter.

Make sure the O-ring is not stuck to the fuel filter head.

Remove the O-ring if necessary.

Замена элементов топливной системы Cummins ISF3.8

Lubricate the O-ring with clean oil.

Install the fuel filter onto the filter cover. Screw on the filter until it contacts the cover. Use a puller to tighten the filter 3/4 turn. Tightening torque 23 Nm

Note: Do not add fuel to the fuel filter beforehand.

Prime the low pressure fuel system using a hand pump (140 to 150 strokes for a dry filter).

Start the engine. If the engine does not start within 30 seconds, turn off the ignition.

Run the fuel priming pump again, repeating the above operations until the engine starts.

If the engine starts, it is possible that it will run erratically and noisy for the first few minutes, which is not a malfunction.