Chrysler 300/300 Touring/300C, Dodge Magnum. Manual - part 1790

Injector opens (start of injection)

The solenoid valve is energized with the pickup current which serves to ensure that it open quickly. The force
exerted by the triggered solenoid now exceeds that of the valve spring and the armature opens the bleed orifice.
Almost immediately, the high-level pick-up current is reduced to the lower holding current required for the electro-
magnet. This is possible due to the magnetic circuit’s air gap now being smaller. When the bleed orifice opens, fuel
can flow from the valve control chamber into the cavity situated above it, and from there via the fuel return to the
tank. The bleed orifice prevents complete pressure balance, and the pressure in the valve control chamber sinks as
a result. This leads to the pressure in the valve-control chamber being lower than that in the nozzle’s chamber
volume which is still at the same pressure level as the rail. The reduced pressure in the valve-control chamber
causes a reduction in the force exerted on the control plunger, the nozzle needle open as a result, and injection
starts.

Injector opens fully

The control plunger reaches its upper stop where it remains supported by a cushion of fuel which is generated by
the flow of fuel between the bleed and feed orifices. The injector nozzle has now opened fully, and the fuel is
injected into the combustion chamber at a pressure almost equal to that in the fuel rail.

Injector closes (end of injection)

As soon as the solenoid valve is no longer triggered, the valve spring forces the armature downwards and the ball
closes the bleed orifice. The armature is a 2–piece design. Here, although the armature plate is guided by a driver
shoulder in its downward movement, it can “overspring” with the return spring so that it exerts no downwards-acting
forces on the armature and the ball. The closing of the bleed orifice lead to pressure build up in the control chamber
via the input from the feed orifice. This pressure is the same as that in the rail and exerts an increased force on the
control plunger through its end face. This force, together with that of the spring, now exceeds the force exerted by
the chamber volume and the nozzle needle closes. Injection ceases as soon as the nozzle needle comes up against
its bottom stop again .

STANDARD PROCEDURE

CLEANING FUEL INJECTORS

NOTE: Before cleaning the injector recesses, seal
the injector holes in the injector recesses with the
appropriate pin to prevent debris from falling into
the recesses and entering the motor.

1. Using a lint-free rag, wipe the cylinder head around

the fuel injector.

2. Wipe out injector recesses with a lint-free cloth,

then clean with a cylinder brush.

3. Clean the bottom of the cylinder recess with a

round brush.

4. Blow out the recess and clean again with a lint-free

cloth and cover over.

5. Perform these steps for each injector recess.

NOTE: DO NOT clean the tip of the injector with a
wire brush. Use a lint—free cloth.

6. Clean injector body with a wire brush.

7. Clean injector tips with a lint-free cloth.

NOTE: Do Not apply antiseize lubricant to the injector nozzle, apply only to the injector body.

8. Grease injector body with antiseize lubricant.

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FUEL INJECTION - DIESEL

NOTE: Always replace the seals that seal off the injectors at the cylinder head to the combustion chamber.

INJECTOR CLASSIFICATION

The classification of injectors describes the quantity characteristic of the injector. This will make it possible to match
the engine software to the tolerances of the injector within a more narrowly graduated range. Classification can be
clearly recognized, and assigned only by means of a scantool.

Classified injectors can be recognized by the six-digit alphanumeric code or part number and identification on the
magnetic head. The number corresponds to the classification stage.

These general conditions equally apply if, as a result of replacing an engine, carrying out repairs to the cylinder
head etc., the cylinder selective assignment of the injectors or the engine control module assignment may have
changed. If proper attention is not paid to the classification on these vehicles driveability and smoking concerns
could result.

If an injector(s) is replaced, or if there is any concern that an injector may not be installed in its original location, it
is then necessary to assign the classification number to the corresponding cylinder with the scantool in the control
module.

INJECTOR CLASSIFICATION PROCEDURE

1. Turn ignition switch “ON”.

2. Using a scantool, select ENGINE then MISCELLANEOUS.

3. Select LEARN INJECTORS.

4. Using the up and down arrows, scroll to the appropriate injector.

5. Using the right and left arrows, set injector to proper classification.

6. Once injectors are classified, cycle ignition to complete.

REMOVAL

LEFT CYLINDER HEAD

WARNING: (Refer to 14 - FUEL SYSTEM - WARNING). No sparks, open flames or smoking. Risk of poisoning
from inhaling and swallowing fuel. Risk of injury to eyes and skin from contact with fuel. Pour fuels only
into suitable and appropriately marked containers. Wear protective clothing.

1. Disconnect negative battery cable.

2. Remove engine cover.

3. Disconnect the fuel return hose at the injector by lifting up on retaining tab and wiggling hose free.

4. Loosen the high pressure fuel lines at the fuel rail.

5. Disconnect the high pressure line at the fuel injector.

6. Disconnect the fuel injector electrical connector.

7. Remove the fuel injector hold down.

NOTE: If injectors are tight, remove with special tool 9552.

8. Remove injectors and discard lower sealing washer.

9. Clean injectors and recesses.

RIGHT CYLINDER HEAD

1. Disconnect negative battery cable.

2. Remove engine cover.

3. Disconnect the fuel return hose at the injector by lifting up on retaining tab and wiggling hose free.

FUEL INJECTION - DIESEL

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4. Loosen the high pressure fuel lines at the fuel rail.

5. Disconnect the high pressure fuel lines at the fuel injector.

6. Disconnect the fuel injector electrical connector.

7. Remove the fuel injector hold down.

NOTE: If injectors are tight, remove with special tool 9552.

8. Remove injectors and discard lower sealing washer.

9. Clean injectors and recesses.

INSTALLATION

LEFT CYLINDER HEAD

1. Clean injectors and recesses.

NOTE: Do Not apply any lubricant to the fuel injector nozzle. Care must be taken not to restrict the dis-
charge orifices in the nozzle.

2. Coat injector body with anti seize lubricant then install injectors with new sealing washers.

3. Install tensioning claws. Tighten fasteners in two stages, 7 N·m (62 lbs. in.) then 180°.

CAUTION: Inspect both ends of the fuel line and fittings. If there is any damage to the sealing surface,
replace the fuel line.

4. Position fuel return line at injectors, hand tighten the high pressure fuel line at the fuel rail and at the injector.

5. Tighten the fuel line fitting at the fuel rail to 27 N·m ( 20ft. lbs.), and tighten the fuel line at the injector to 27 N·m

(20 ft. lbs.).

6. Reconnect the fuel injector electrical connector.

NOTE: For the left rear injector, position the engine wiring harness and tighten the harness fasteners to 8.5
N·m (75 in. lbs.).

7. Install the return fuel hose on the injector and push down on the retaining ring.

8. Connect negative battery cable.

9. Install engine cover.

10. Start engine, allow to warm, turn engine off and inspect for leaks.

RIGHT CYLINDER HEAD

1. Clean injectors and recesses.

NOTE: Do Not apply any lubricant to the fuel injector nozzle. Care must be taken not to restrict the dis-
charge orifices in the nozzle.

2. Coat injector body with anti seize lubricant then install injectors with new sealing washers.

3. Install tensioning claws. Tighten fasteners in two stages, 7 N·m (62 lbs. in.) then 180°.

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FUEL INJECTION - DIESEL

CAUTION: Inspect both ends of the fuel line and fittings. If there is any damage to the sealing surface,
replace the fuel line.

4. Position fuel return line at injectors, hand tighten the high pressure fuel line at the fuel rail and at the injector.

5. Tighten the fuel line fitting at the fuel rail to 27 N·m ( 20 ft. lbs.), and tighten the fuel line at the injector to 27 N·m

(20 ft. lbs.).

6. Reconnect the fuel injector electrical connector.

7. Install the return fuel hose on the injector and push down on the retaining ring

8. Connect negative battery cable.

9. Install engine cover.

10. Start engine, allow to warm, turn engine off and inspect for leaks.

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