Dodge Nitro. Manual - part 676

Fig. 81: Fuel Pressure Solenoid Operation 
Courtesy of CHRYSLER LLC 

High pressure which is present in the fuel rail flows to the ball seat (1) of the pressure solenoid. The specified 
pressure required by the system is built up in the rail by the fuel pressure solenoid building up a magnetic force 
which corresponds to this specific pressure by means of a control current from the Electronic Control Module 
(ECM). This magnetic force equals a certain outlet cross section at the ball seat of the valve. The rail pressure is 
altered as a result of the quantity of fuel which flows off. The current fuel pressure is signaled by the fuel rail 
pressure sensor to the engine control module (ECM). The controlled fuel flows back along the return fuel line, 
into the tank. 

In a de-energized state, the fuel pressure solenoid is closed as the spring force (2) presses the ball into the ball 
seat. When driving, the fuel pressure solenoid is constantly open. When engine is started, the fuel pressure 
solenoid is held closed by magnetic force. When driving, the pressure of the fluid counteracts the magnetic 
force of the coil and the slight spring force. 

REMOVAL 

FUEL PRESSURE SOLENOID 

Review the high pressure fuel system warning before beginning repair. See WARNING.  

1 - BALL SEAT
2 - SPRING FORCE
3 - MAGNETIC FORCE
4 - COIL
5 - FUEL PRESSURE SOLENOID
6 - HIGH PRESSURE SUPPLY

 

2007 Dodge Nitro R/T 

2007 ENGINE Fuel System - Nitro

  

Fig. 82: Exploded View Of Fuel Rail - 2.8L Diesel 
Courtesy of CHRYSLER LLC 

1. Disconnect negative battery cable. 

2. Clean the area around the fuel pressure solenoid with Mopar® Throttle Body Cleaner P/N 04897156AA 

or equivalent degreasing solvent and compressed air.  

3. Disconnect the fuel pressure solenoid harness connector. 

WARNING:

High pressure fuel spray can cause severe cuts, and is extremely 
flammable. Before opening any part of the high pressure fuel system, wait 
for a minimum of 30 seconds after turning off the engine to allow 
pressure to bleed down from the high pressure side of the fuel system. 
Otherwise severe personal injury can result when the high pressure fuel 
system is opened.

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.

NOTE:

Do allow cleaning solvent or debris to enter the fuel pressure solenoid 
harness connector.

 

2007 Dodge Nitro R/T 

2007 ENGINE Fuel System - Nitro

  

4. Remove fuel rail. See REMOVAL.  

5. Clamp fuel rail (2) securely in vise with protective jaws. 

6. Counterhold the fuel rail and unscrew the fuel pressure solenoid (3). 

7. Use a clean plug to close off the fuel rail pressure solenoid opening if the fuel pressure solenoid will not 

be immediately re-installed.  

INSTALLATION 

FUEL PRESSURE SOLENOID 

Review the high pressure fuel system warning before beginning repair. See WARNING.  

WARNING:

When working with parts on the high side of the fuel injection 
system such as the fuel rail and high pressure injector lines, slowly 
loosen the part to allow any residual pressure to bleed down from 
the high pressure side of the system.

CAUTION: Once removed, the solenoid must always be replaced. Do not re-use 

a fuel pressure solenoid that has been installed in the fuel rail.

NOTE:

Do not allow dirt or debris to enter the fuel rail and fuel rail solenoid 
threads after the fuel pressure solenoid has been removed from the fuel 
rail.

 

2007 Dodge Nitro R/T 

2007 ENGINE Fuel System - Nitro

  

Fig. 83: Exploded View Of Fuel Rail - 2.8L Diesel 
Courtesy of CHRYSLER LLC 

1. Position the fuel rail (2) into a soft jawed vise.  

2. Inspect the sealing surfaces of the fuel pressure solenoid opening in the fuel rail. If any cuts or gouges are 

present in the fuel rail pressure solenoid opening, replace the fuel rail.  

3. Lubricate the fuel pressure solenoid sealing rings with clean diesel fuel. Do not allow dirt or debris to 

come in contact with the fuel rail solenoid or the threads in the fuel rail. 

WARNING:

Before working on an open fuel system, eliminate any source of sparks or 
open flames near the work area, and do not smoke. Wash diesel fuel off 
skin as soon as possible to avoid the risk of poisoning from inhaling and 
swallowing fuel. Do not allow diesel fuel to come in contact with eyes, 
otherwise, severe injury can result from contact with fuel. Pour fuels only 
into suitable and appropriately marked containers. Wear protective 
clothing whenever possible to avoid injury.

CAUTION: There is a special tightening procedure for the fuel rail solenoid that must 

be followed along with the proper use of a torque wrench. Therefore the 
fuel rail must be removed before installing the fuel pressure solenoid.

CAUTION: Do not reuse an existing fuel pressure solenoid. A new fuel pressure 

solenoid must be installed any time the existing solenoid has been 
removed from the fuel rail.

 

2007 Dodge Nitro R/T 

2007 ENGINE Fuel System - Nitro