1971 buick 455 fuel pump diagram

Yeah, quit trying to play auto mechanic an take it to a qualified repair shop. You have no clue how it works.

Fuel Gage Inaccurate or Inoperative (Buick)

Turn the ignition switch to the RUN position.
Using a scan tool, inspect for Powertrain Control Module (PCM) diagnostic trouble codes (DTCs). Refer to Engine Controls in order to diagnose PCM DTCs.
Turn the ignition switch to the OFF position.
Disconnect the fuel tank unit connector.
Connect the 2 red leads from the J 33431-C to the harness connector terminal B and terminal D.
Turn the ignition switch to the RUN position.
Set the tester resistance dials to 40 ohms (EMPTY).
Set the tester resistance dials to 248 ohms (FULL).
Does the fuel gauge display E at 40 ohms and F at 248 ohms?


Fuel Gauge (Buick, Pontiac)
The magnetic fields of the 2 coils move the fuel gauge pointer. The coils are at right angles to each other. The 2 coils are connected to each other. The fuel level Pulse-Width Modulated (PWM) circuit from the PCM connects at a middle point. Battery voltage is applied to the end of the coil at the E end. Ground is applied at the other coil's F end.
The fuel level sender resistance is proportional to the fuel level. The voltage across the sender is the fuel level input signal that is applied to the PCM on CKT 30 and CKT 452. The PCM provides a Pulse-Width Modulated (PWM) fuel level output signal on CKT 455 (PPL/WHT) to the instrument cluster fuel gauge.
When the tank is low, the fuel level sender resistance is low. A larger current passes through the E coil in order to move the pointer toward E on the scale. When the tank is full, the sender resistance is high. More current flows through the F coil. This moves the pointer toward F on the scale.
With 2 coils operating the pointer, the gauge is not affected by changes in the vehicle's electrical system.

In the link. you can also click on the images tab.

https://www.google.com/search?q=vacuum+diagram+for+a+1985+Buick+Regal+Limited+3.8

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I had a 1971 f900 truck , which is a gas engine vehicle, that we used in the harvesting of silage and grain. It had a 534 cid engine and had a mechanical fuel pump which does not require a fuel pump relay. That said, someone could have added an electric pump which could use a relay. Follow the fuel line from the carburetor to the tank. A mechanical pump will be connected to the engine. An electric pump would be inline or in the fuel tank.

They should be 2 different size hoses so can't get them wrong. if you replaced the fuel pump/guage in tank may be bad. can try to cycle the key a few times.

Try this:

Your wish is my command. here is '74 Riviera 455

Yes ,,instructions are below, Use eye protection for this procedure
Remove or Disconnect:

1. Relieve Fuel Pressure
2. Disconnect negative battery cable
3. Raise vehicle on hoist
4. Remove Fuel Tank
5. Remove Fuel Gage sending and pump assembly by turning cam lock ring counterclockwise. Lift assembly from fuel tank and remove fuel pump from fuel gage sender unit.
6. Disconnect pump wires, hose clamps, and clamp around pump body
7. Pull pump assembly out of rubber connectors
8. Inspect fuel pump attaching hose for any signs of deterioration. Replace as necessary.

Install or Connect:

1. Push fuel pump assembly into attaching hose
2. Connect pump wires, hose clamps at attaching hose and around pump body
3. Place Fuel tank sending unit and pump assembly into tank using new O-ring
4. Place cam lock over assembly and lock by turning clockwise
5. Install Fuel Tank
6. Start engine and check fuel pipe connector for visual leaks

junk in fuel tank, injectors probably got a little resticted. How bad was the gas? hook a hose to the fuel rail and bleed most of the bad stuff out of the system turning key to on position to activate fuel pump. The pump has a screen on it in tank but thats alot of work to get to. A little injector cleaner or octane booster would be an advantage in the tank

Fuel level sensor is in the fuel tank,in with the fuel pump,and fuel sending unit.

You will have to drop the fuel tank. It is nn the tank. dran fueal use jack stands to surport auto. I use a floor jack ti lower the tank. Take car to un hook the hoses to the tank and the fuel level wires.