Fuel Filter Change/clean

[2005 Z71]

How do you change/clean the fuel filter on a Silverado? Any help would be great.

 

The guys at the oil shop said they have a treatment that they do for around 50-75 bucks. Just unsure if that is the best way to go, or if this is something I can do myself with adding some fuel treatments or something.

[redvett]

What year is your truck? 2004 & up have a lifetime of the fuel pump filter along with the returnless fuel system.

[2005 Z71]

Redvett I appreciate your response. This is a gray area for me. Can you give me more information on how the returnless fuel system is setup. My truck is the 05 5.3 model. Does this mean there is nothing to change out?

[MS3DALE]

This should help....

 

Document ID# 1732878

2005 Chevrolet Chevy K Silverado - 4WD

 

Fuel System Description (Pick-up and Utility)

Fuel System Overview

The Fuel System is a returnless on-demand design. The fuel pressure regulator is a part of the fuel sender assembly, eliminating the need for a return pipe from the engine. A returnless fuel system reduces the internal temperature of the fuel tank by not returning hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.

 

An electric turbine style fuel pump attaches to the fuel sender assembly inside the fuel tank. The fuel pump supplies high pressure fuel through the fuel filter and the fuel feed pipe to the fuel injection system. The fuel pump provides fuel at a higher rate of flow than is needed by the fuel injection system. The fuel pump also supplies fuel to a venturi pump located on the bottom of the fuel sender assembly. The function of the venturi pump is to fill the fuel sender assembly reservoir. The fuel pressure regulator, a part of the fuel sender assembly, maintains the correct fuel pressure to the fuel injection system. The fuel pump and sender assembly contains a reverse flow check valve. The check valve and the fuel pressure regulator maintain fuel pressure in the fuel feed pipe and the fuel rail in order to prevent long cranking times.

 

Fuel Tanks

The fuel tanks store the fuel supply. The front fuel tank is located on the left side of the vehicle. On dual-tank applications, the secondary fuel tank is located in the rear of the vehicle above the spare tire. The fuel tanks are each held in place by 2 metal straps that attach to the frame. The fuel tanks are molded from high density polyethylene.

 

Fuel Fill Pipe

The fuel fill pipe has a built-in restrictor in order to prevent refueling with leaded fuel. When refueling dual tank applications, fuel is dispensed to both the front and rear fuel tanks at the same time. Once the fill vent is obstructed, fuel backs up the fill pipe and trips the dispensing nozzle. The front fuel tank vent runs into the rear tank to the top of the filler pipe assembly, which in turn vents to atmosphere. The fuel tank vent valves are connected and route to the canister to collect hydrocarbon emissions during operation of the vehicle.

 

Fuel Filler Cap

 

The fuel fill pipe has a tethered fuel filler cap. A torque-limiting device prevents the cap from being over tightened. To install the cap, turn the cap clockwise until you hear clicks. This indicates that the cap is correctly torqued and fully seated. A built-in device indicates that the fuel filler cap is fully seated. A fuel filler cap that is not fully seated may cause a malfunction in the emission system.

 

Fuel Sender Assembly

 

The front fuel sender on dual tank applications consists of the following major components:

 

• The fuel level sensor

 

• The fuel tank fuel pump module

 

• The fuel strainer

 

• The fuel filter

 

 

 

 

 

The rear fuel sender on dual tank applications consists of the following major components:

 

• The fuel level sensor (4)

 

• The FTP sensor (1)

 

• The rear fuel pump (2)

 

 

 

 

 

The fuel sender assembly on single tank applications consists of the following major components:

 

• The fuel level sensor

 

• The fuel tank pressure (FTP) sensor

 

• The fuel tank fuel pump module

 

• The fuel strainer

 

• The fuel filter

 

Fuel Level Sensor

The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor cord. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor, which changes resistance in correspondence to the amount of fuel in the fuel tank. The powertrain control module (PCM) sends the fuel level information via the class 2 circuit to the instrument panel (I/P) cluster. This information is used for the I/P fuel gage and the low fuel warning indicator, if applicable. The PCM also monitors the fuel level input for various diagnostics.

 

Fuel Pump

The fuel pump is mounted in the fuel sender assembly reservoir. The fuel pump is an electric high pressure pump. Fuel is pumped to the fuel rail at a specified flow and pressure. The fuel pump delivers a constant flow of fuel to the engine during low fuel conditions and aggressive vehicle maneuvers. The powertrain control module (PCM) controls the electric fuel pump operation through a fuel pump relay. The fuel pump flex pipe acts to dampen the fuel pulses and noise generated by the fuel pump.

 

Rear Fuel Pump (Dual Tank Applications Only)

On dual tank applications, the rear fuel pump is located in the rear fuel tank. The rear fuel pump is powered by a secondary fuel pump relay when the fuel level drops below a predetermined value. Fuel is transferred from the rear fuel tank to the front fuel tank in order to ensure all of the usable fuel volume is available to the front fuel pump. The secondary fuel pump relay supply voltage is received from the primary fuel pump relay when the front fuel pump is energized.

 

Fuel Strainer

The fuel strainer attaches to the lower end of the fuel sender. The fuel strainer is made of woven plastic. The functions of the fuel strainer are to filter contaminants and to wick fuel. Fuel stoppage at this point indicates that the fuel tank contains an abnormal amount of sediment.

 

Fuel Filter

The fuel filter is contained in the fuel sender assembly inside the fuel tank. the paper filter element of the fuel filter traps particles in the fuel that may damage the fuel injection system. The fuel filter housing is made to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There is no service interval for fuel filter replacement.

 

Nylon Fuel Pipes

Caution: Refer to Fuel and EVAP Pipe Caution in Cautions and Notices.

 

Nylon pipes are constructed to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There are 3 sizes of nylon pipes used: 9.5 mm (3/8 in) ID for the fuel supply, 7.6 mm (5/16 in) ID for the fuel return, and 12.7 mm (1/2 in) ID for the vent. Heat resistant rubber hose or corrugated plastic conduit protects the sections of the pipes that are exposed to chafing, to high temperatures, or to vibration.

 

Nylon fuel pipes are somewhat flexible and can be formed around gradual turns under the vehicle. However, if nylon fuel pipes are forced into sharp bends, the pipes kink and restrict the fuel flow. Also, once exposed to fuel, nylon pipes may become stiffer and are more likely to kink if bent too far. Take special care when working on a vehicle with nylon fuel pipes.

 

Quick-Connect Fittings

Quick-connect fittings provide a simplified means of installing and connecting fuel system components. The fittings consist of a unique female connector and a compatible male pipe end. O-rings, located inside the female connector, provide the fuel seal. Integral locking tabs inside the female connector hold the fittings together.

 

On-Board Refueling Vapor Recovery System (ORVR)

The On-Board Refueling Vapor Recovery System (ORVR) is an on-board vehicle system designed to recover fuel vapors during the vehicle refueling operation. The flow of liquid fuel down the fuel filler pipe provides a liquid seal which prevents vapor from leaving the fuel filler pipe. An evaporative emission (EVAP) pipe transports the fuel vapor to the EVAP canister for use by the engine.

 

Fuel Pipe O-Rings

O-rings seal the threaded connections in the fuel system. Fuel system O-ring seals are made of special material. Service the O-ring seals with the correct service part.

 

Fuel Rail Assembly

 

The fuel rail assembly attaches to the engine intake manifold. The fuel rail assembly performs the following functions:

 

• Positions the injectors (3) in the intake manifold

 

• Distributes fuel evenly to the injectors

 

• Integrates the fuel dampener (2) into the fuel metering system

 

Fuel Injectors

The fuel injector assembly is a solenoid device controlled by the powertrain control module (PCM) that meters pressurized fuel to a single engine cylinder. The PCM energizes the injector solenoid to open a normally closed ball valve. This allows the fuel to flow into the top of the injector, past the ball valve, and through a director plate at the injector outlet. The director plate has machined holes that control the fuel flow, generating a spray of finely atomized fuel at the injector tip. Fuel from the injector tip is directed at the intake valve, causing the fuel to become further atomized and vaporized before entering the combustion chamber. This fine atomization improves fuel economy and emissions.

 

Fuel Pressure Regulator

The fuel pressure regulator is contained in the fuel sender assembly.

 

Fuel Metering Modes of Operation

The powertrain control module (PCM) monitors voltages from several sensors in order to determine how much fuel to give the engine. The PCM controls the amount of fuel delivered to the engine by changing the fuel injector pulse width. The fuel is delivered under one of several modes.

 

 

Starting Mode

When the ignition is first turned ON, the PCM energizes the fuel pump relay for 2 seconds. This allows the fuel pump to build pressure in the fuel system. The PCM calculates the air/fuel ratio based on inputs from the engine coolant temperature (ECT), mass air flow (MAF), manifold absolute pressure (MAP), and throttle position (TP) sensors. The system stays in starting mode until the engine speed reaches a predetermined RPM.

 

 

Clear Flood Mode

If the engine floods, clear the engine by pressing the accelerator pedal down to the floor and then crank the engine. When the TP sensor is at wide open throttle (WOT), the PCM reduces the fuel injector pulse width in order to increase the air to fuel ratio. The PCM holds this injector rate as long as the throttle stays wide open and the engine speed is below a predetermined RPM. If the throttle is not held wide open, the PCM returns to the starting mode.

 

 

Run Mode

The run mode has 2 conditions called Open Loop and Closed Loop. When the engine is first started and the engine speed is above a predetermined RPM, the system begins Open Loop operation. The PCM ignores the signal from the heated oxygen sensors (HO2S). The PCM calculates the air/fuel ratio based on inputs from the ECT, MAF, MAP, and TP sensors. The system stays in Open Loop until meeting the following conditions:

 

• Both front HO2S have varying voltage output, showing that both HO2S are hot enough to operate properly.

 

• The ECT sensor is above a specified temperature.

 

• A specific amount of time has elapsed after starting the engine.

 

Specific values for the above conditions exist for each different engine, and are stored in the electrically erasable programmable read-only memory (EEPROM). The system begins Closed Loop operation after reaching these values. In Closed Loop, the PCM calculates the air/fuel ratio, injector ON time, based upon the signal from various sensors, but mainly from the HO2S. This allows the air/fuel ratio to stay very close to 14.7:1.

 

 

Acceleration Mode

When the driver pushes on the accelerator pedal, air flow into the cylinders increases rapidly. To prevent possible hesitation, the PCM increases the pulse width to the injectors to provide extra fuel during acceleration. This is also known as power enrichment. The PCM determines the amount of fuel required based upon the TP, the ECT, the MAP, the MAF, and the engine speed.

 

 

Deceleration Mode

When the driver releases the accelerator pedal, air flow into the engine is reduced. The PCM monitors the corresponding changes in the TP, the MAP, and the MAF. The PCM shuts OFF fuel completely if the deceleration is very rapid, or for long periods, such as long, closed-throttle coast-down. The fuel shuts OFF in order to prevent damage to the catalytic converters.

 

 

Battery Voltage Correction Mode

When the battery voltage is low, the PCM compensates for the weak spark delivered by the ignition system in the following ways:

 

• Increasing the amount of fuel delivered

 

• Increasing the idle RPM

 

• Increasing the ignition dwell time

 

 

Fuel Cutoff Mode

The PCM cuts OFF fuel from the fuel injectors when the following conditions are met in order to protect the powertrain from damage and improve driveability:

 

• The ignition is OFF. This prevents engine run-on.

 

• The ignition is ON but there is no ignition reference signal. This prevents flooding or backfiring.

 

• The engine speed is too high, above red line.

 

• The vehicle speed is too high, above rated tire speed.

 

• During an extended, high speed, closed throttle coast down--This reduces emissions and increases engine braking.

 

• During extended deceleration, in order to prevent damage to the catalytic converters

 

Fuel Trim

The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. The PCM monitors the heated oxygen sensor (HO2S) signal voltage while in Closed Loop and regulates the fuel delivery by adjusting the pulse width of the fuel injectors based on this signal. The ideal fuel trim values are around 0 percent for both short term and long term fuel trim. A positive fuel trim value indicates the PCM is adding fuel in order to compensate for a lean condition by increasing the pulse width. A negative fuel trim value indicates that the PCM is reducing the amount of fuel in order to compensate for a rich condition by decreasing the pulse width. A change made to the fuel delivery changes the short term and long term fuel trim values. The short term fuel trim values change rapidly in response to the HO2S signal voltage. These changes fine tune the engine fueling. The long term fuel trim makes coarse adjustments to the fueling in order to re-center and restore control to short term fuel trim. A scan tool can be used to monitor the short term and long term fuel trim values. The long term fuel trim diagnostic is based on an average of several of the long term speed load learn cells. The PCM selects the cells based on the engine speed and engine load. If the PCM detects an excessive lean or rich condition, the PCM will set a fuel trim diagnostic trouble code (DTC).

 

 

Document ID# 1732878

2005 Chevrolet Chevy K Silverado - 4WD

[MS3DALE]

You might want to read this also....

 

Document ID# 1549585

2005 Chevrolet Chevy K Silverado - 4WD

 

Fuel System Cleaning

Fuel Tank Cleaning

Important:

 

• Only use oil free compressed air to blow out the fuel pipes.

 

• Inspect the fuel tank internally and clean the fuel tank if you find a plugged fuel filter.

 

 

Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .

Remove the fuel sender assembly. Refer to Fuel Sender Assembly Replacement .

Inspect the fuel pump strainer. Replace a contaminated strainer and inspect the fuel pump.

Inspect the fuel pump inlet for dirt and debris. Replace the fuel pump if you find dirt or debris in the fuel pump inlet.

Important: When flushing the fuel tank, handle the fuel and water mixture as a hazardous material. Handle the fuel and water mixture in accordance with all applicable local, state, and federal laws and regulations.

 

Flush the fuel tank with hot water.

Pour the water out of the fuel sender assembly opening. Rock the tank to be sure that removal of the water from the tank is complete.

Remove the fuel rail assembly. Refer to Fuel Rail Assembly Replacement .

Drain the fuel from the fuel rail. It will be necessary to remove the fuel injectors from the fuel rail to properly clear all debris from the fuel rail and fuel injectors. Use light shop air to remove any debris from the fuel rail and injectors.

Replace the fuel injector O-rings.

Use light shop air in the opposite direction of the fuel flow in order to remove any debris from the fuel lines. Catch any fuel from the fuel lines with an approved gasoline container.

Install the injectors to the fuel rail.

Install the fuel rail assembly onto the engine. Refer to Fuel Rail Assembly Replacement .

If equipped with a serviceable fuel filter, replace the fuel filter.

Install the fuel sender assembly. Refer to Fuel Sender Assembly Replacement .

Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .

Important: If the fuel pump or sender assembly was not replaced, purge the fuel sender assembly.

 

Purge the fuel sender assembly.

16.1. Disconnect the fuel feed line from the fuel filter, if equipped. Otherwise, disconnect the fuel feed line at the fuel tank.

 

16.2. Connect a length of hose to the fuel feed pipe.

 

16.3. Insert the other end of the hose into an empty 3.8 liter (1 gallon) approved gasoline container.

 

16.4. Add 23 liters (6 gallons) of clean fuel into the fuel tank.

 

16.5. Turn on the fuel pump using the scan tool until 2 liters (1/2 gallon) of fuel flows into the fuel container.

 

Inspect for leaks.

17.1. Turn the ignition switch ON for 2 seconds.

 

17.2. Turn the ignition switch OFF for 10 seconds.

 

17.3. Turn the ignition switch ON.

 

17.4. Inspect for fuel leaks.

 

Document ID# 1549585

2005 Chevrolet Chevy K Silverado - 4WD

[C & A s Dad]

I have certainly learned something from this. I did not know these systems did not rtn fuel to the tank as in the past. I guess if I still worked the counter I would have known this.

 

Thanks for the info Rich and Redvett.

[pm26]

So, if somehow the filter gets plugged, instead of replacing a $10 filter, now one has to drop the tank and go through all this? What moron came up with this brilliant idea? I can understand the returnless fuel system, but what possible reason, other than being cheap, is there for not providing a disposable fuel filter in a convenient location?.

[WFO]

So, if somehow the filter gets plugged, instead of replacing a $10 filter, now one has to drop the tank and go through all this? What moron came up with this brilliant idea? I can understand the returnless fuel system, but what possible reason, other than being cheap, is there for not providing a disposable fuel filter in a convenient location?.

 

 

It the engineer thought it looked good on paper.

[unit731]

So, if somehow the filter gets plugged, instead of replacing a $10 filter, now one has to drop the tank and go through all this? What moron came up with this brilliant idea? I can understand the returnless fuel system, but what possible reason, other than being cheap, is there for not providing a disposable fuel filter in a convenient location?.

 

 

AMEN !

[redvett]

This change was required by the EPA to reduce vapor emissions. The system is used on almost all brands and has been in use since the 90's. One good thing about not returning the fuel is it stays cooler and the result is a bit more power.

[JoshRDavis.84]

I used to change the fuel filter on my 2001 every 15,000 miles. I am guessing that the setup on my 2006 is very similar if not the same as the 2005 listed above. Does this mean that I never need to replace my filter? My dealer reccomended every 30,000 miles. What about bypassing the intank filter and splicing the hard line with an easily replaceable filter?

 

Thanks for any feedback