The 2003 Chevy avalanche came principles with a 5.3-liter eight-cylinder engine and a four-speed automatic transmission. The fuel pump on your Avalanche is located inside the fuel vat and may be the explanation of sluggish performance or a non-starting engine. The fuel systems consists of the fuel pump and strainer, fuel lines, fuel filter, fuel impulse regulator, fuel inveigh and fuel injectors. Remove the scan tool from the vehicle and turn the ignition key to the "Off" position. Open the valve on the pressure gauge to relieve the fuel pressure. Disconnect the fuel pressure gauge and install the Schrader valve cap.
Grassland the vehicle on a exact surface and establish the parking brake. Turn the ignition to the "Off" position. Lift the hood and advice it with the hood prop rod. Remove the bolt securing the plastic insert to the top of the engine with the socket and ratchet.
2. Set the fuel castigate that is over the intake manifold and asset the Schrader valve; it has a ebon cap. Remove the cap to expose the valve. Wrap a shop rag encircling the valve and slowly depress the valve with a screwdriver to cooperate fuel compel.
3. Install the fuel strength gauge onto the Schrader valve and turn the gauge valve to the closed position. Squeeze the tabs for the accelerated disconnect becoming on the fuel send limit, and seperate the return line from the fuel castigate. Install the fuel shut-off include between the fuel rail and reimburse border by clicking them into settle.
4. Install the interpret baggage to the OBD-II Harbour below the Chauffeur side dashboard. Turn on the discover effects and concede it to convey with the vehicle pc. Provided obligatory, enter requested news such as compose, example and year. Attach the 3/8-inch rubber hose to the contrary purpose of the fuel compel gauge.
5. Enter "diagnostics" income on the scrutinize stuff, then accept "fuel step." Conduct the rubber hose from the impulse gauge to the humble Gauze can. Turn the shut-off encompass valve to the sincere position. Enable the fuel pump and slowly unlocked the coercion gauge valve to bleed any air from the fuel step. Brisk the valve when there no longer is any air or hissing clamour prospect from the rubber hose. The diagnostic announce belongings should chalk up turned off the fuel pump; if not, select the option on the scan tool to turn off the fuel pump.
6. Watch the fuel pressure gauge and turn the fuel pump on with the scan tool. Proper fuel pressure is 62 psi for gasoline and 54 psi for E85 engines. If the fuel pressure does not rise to or above the required psi, inspect the fuel sending lines for any leaks and replace the fuel filter, then proceed to the next step. If the fuel pressure exceeded the pressure requirements and the engine still is sluggish or does not start, inspect and replace the fuel pressure regulator and test drive the vehicle.
7. Again check the fuel pressure after replacing the fuel filter and any damaged fuel lines. If the pressure still does not meet the required psi, visually inspect the fuel pump wire harness connector for damage or corrosion, and inspect the ground wire that travels from the fuel pump to the frame rail. Replace any damaged wire or harness. Check the fuel pressure after repairing any wiring damage; if there are no damaged wires or the pressure doesn't meet the required psi, replace the fuel pump and fuel strainer.
8. To check the fuel pump true and efficiently diagnose the fuel pump, there are a infrequent speciality tools needed, nevertheless they generally are available to rent at parts stores.
Instructions
1.9. Squeeze the tabs for the fuel shut-off insert quick connect fittings and remove the insert from between the fuel rail and return line. Connect the return line to the fuel rail by clipping the line into the fitting on the fuel rail. Install the plastic engine cover and tighten the retaining nut snug with the socket and ratchet. Shut the vehicle hood and test drive the vehicle to ensure the engine is running smoothly.
