How do i chang the fuel pressure regulator its not behind the fuel meter body is it under the intake? on a 2002 gmc sonoma ex cab.

It's a guess, but yes, you have one or more stuck injectors and when you power off the pressurized gas in the system is going into the combustion chambers and seeping past the piston rings. When you pull the relay, it is running on the fumes from the oil pan.

You need an auto electrician, a professional grade scan tool computer can diagnose in 30 minutes.

https://www.google.com/search?q=mobile+auto+electrician+near+me

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FPR, 4.3L
SM quote
the fuel pressure regulator, part of the fuel rail assembly, keeps the fuel available to the injectors at a regulated pressure. A separate pipe returns any unused fuel to the fuel tank.
The fuel meter body assembly?(1) attaches to the lower intake manifold. The fuel meter body assembly performs the following functions:

• Distributes fuel evenly to the injectors?(12)
• Integrates the fuel pressure regulator?(14) into the fuel metering system

here it is right here #14

some call the ''SPIDER' but what it is tube from the fuel meter body and it is under intake.it consist of fuel injector hold downplate,nuts,fuel injectors,poppet nozzles(tubes),fuel meter body,fuel pressure regulator,o-ring,filter screen.

Get a fuel pressure gauge and connect it to the rail for the fuel injectors to read pressure.

If the pressure is too low, it might be a bad fuel pressure regulator or pump:

Fuel Pressure Regulator Removal & Installation 2.2L Engine To Remove:

1. Relieve the pressure in the fuel system.
2. Disconnect the negative battery cable.
3. Disconnect the vacuum hose from the fuel pressure regulator.
4. Remove the pressure regulator mounting screw.
5. Remove the fuel pressure regulator assembly with O-ring. Inspect filter screen for contamination. If contaminated, remove and discard.

Fuel pressure regulator removal/installation (2.2L SFI engine)

To Install:

1. Apply clean engine oil to the new pressure regulator O-ring and install the O-ring on the regulator.
2. Install the regulator on the fuel rail. Apply thread-locker to the mounting screw.
   • Tighten the screw to 106 lb in (12Nm).
3. Connect the negative battery cable.
4. Use the following procedure to pressurize the fuel system and check for leaks;
5. Turn the ignition ON for 2 seconds.
6. Turn the ignition OFF for 10 seconds.
7. Turn the ignition switch back ON to run the fuel pump again and pressurize the fuel system.
8. Check the fuel rail assembly for fuel leaks.

4.3L Engine RPO L35 To Remove:
4.3L (RPO L35) Fuel meter body assembly

1. Before servicing the vehicle, refer to the Cautions and Warnings in the beginning of this section
2. Remove or disconnect the following:
   • Upper intake manifold (See: Upper Intake Manifold)
   • Fuel pressure regulator retainer clip (M) and discard the clip
   • Regulator (N) from the housing by twisting and pulling the fuel pressure regulator (N) and using a shop towel to catch any spilled fuel
   • Regulator seal O-ring (R) and discard the O-ring seal
   • Regulator filter (Q) and discard the filter
   • Regulator seal O-ring (P) and discard the O-ring seal
   • Backup ring (O) and discard the ring
3. Cover the fuel pressure regulator housing to prevent contamination from entering the fuel system

To Install:
4.3L (RPO L35) Fuel meter body assembly

1. Lubricate the NEW O-ring seals with clean engine oil
2. Assemble the following new parts to the fuel pressure regulator:
   • Backup ring (O)
   • Regulator seal O-ring (P)
   • Regulator filter (Q)
   • Regulator seal O-ring (R)
3. Install or connect the following:
   • Fuel pressure regulator with the vacuum tube pointing down
   • Fuel pressure regulator retainer clip (M)
   • Upper manifold
4. Test drive the vehicle to confirm the repairs

RPO LU3 To Remove:
4.3L (RPO LU3) Fuel meter body assembly

1. Before servicing the vehicle, refer to the Cautions and Warnings in the beginning of this section
2. Remove or disconnect the following:
   • Upper intake manifold
   • Fuel pressure regulator retainer clip (E)
   • Regulator (F) from the housing by twisting and pulling the fuel pressure regulator (F) while using a shop towel to catch any spilled fuel
   • Regulator seal O-ring (J) and discard the O-ring seal
   • Regulator filter (I) and discard the filter
   • Regulator seal O-ring (H) and discard the seal
   • Backup ring (G) and discard the backup ring
3. Cover the fuel pressure regulator housing to prevent contamination from entering the fuel system

To Install:
4.3L (RPO LU3) Fuel meter body assembly

1. Lubricate the NEW O-ring seals with clean engine oil.
2. Assemble the following new parts to the fuel pressure regulator:
   • Backup ring (G)
   • Regulator seal O-ring (H)
   • Regulator filter (I)
   • Regulator seal O-ring (J)
3. Install or connect the following:
   • Fuel pressure regulator (F) with the vacuum tube pointing down
   • Fuel pressure regulator retainer clip (E)
   • Upper intake manifold
4. Test drive the vehicle to confirm the repairs

REMOVAL & INSTALLATION

See Figures 1, 2, 3 and 4
Before performing any service on the front or rear TBI unit, you must place the unit in a suitable holding fixture such as J-9789-118, BT-30-15, or equivalent. If you dont place the unit in a suitable fixture, the throttle valve may be damaged.

1. Disconnect the negative battery cable.
2. Remove the TBI unit from the vehicle, and place it in a suitable holding fixture.
3. Remove the fuel meter cover, as follows:
   1. Remove the 5 fuel meter cover attaching screws and lockwashers.
   
   

Fig. Fig. 1: Exploded view of the fuel meter cover attachment

1. Lift off the fuel meter cover with the fuel pressure regulator (rear unit) or accumulator (front unit), noting their positions for reassembly.
2. Remove and discard the fuel outlet passage only. Leave the fuel meter cover gasket on the fuel meter body.

CAUTION Do NOT remove the 4 screws securing the fuel pressure regulator or accumulator to the fuel meter cover. The regulator or accumulator includes a large spring under heavy compression which, if accidentally released, could cause personal injury. The fuel meter cover is serviced as a complete assembly only. On the rear unit, the fuel meter cover includes the fuel pressure regulator which was calibrated and plugged at the factory.

Fig. Fig. 2: Bottom view of the front and rear fuel meter covers
Do not immerse the fuel meter cover (with the pressure regulator or accumulator) in any type of cleaner. Immersion will damage the internal diaphragms and gaskets.

1. Remove the foam pressure regulator sealing ring (dust seal) from the rear throttle body.

When removing the injector, be careful to avoid damaging the electrical terminals on top of the injector, injector fuel filter and nozzle. Do NOT use pliers to remove the injector, as this could cause damage. The injector cannot be disassembled and is serviced as a complete assembly only. As it is an electrical component, it should not be submerged in any type of cleaner.

1. With the fuel meter cover gasket in place to protect the casting, use a suitable prytool and a fulcrum, as shown in the accompanying figure, to carefully lift the injector until to is free from the fuel meter body.

Fig. Fig. 3: Carefully pry the fuel injector out of the fuel meter body

1. Remove the injector. If removing both injectors, make sure to mark them front and rear, so they can be reinstalled in the proper position. The injectors are NOT interchangeable and cannot be switched during installation.
2. Carefully rotate the injector fuel filter back and forth, then remove the filter from the base of the injector.
3. Remove and discard the fuel meter cover gasket.
4. Remove the large O-ring and steel back-up washer in the top counterbore of the fuel meter body injector cavity. Remove the small O-ring located at the bottom of the injector cavity.

Fuel Pressure Regulator Removal & Installation 2.2L Engine To Remove:

1. Relieve the pressure in the fuel system.
2. Disconnect the negative battery cable.
3. Disconnect the vacuum hose from the fuel pressure regulator.
4. Remove the pressure regulator mounting screw.
5. Remove the fuel pressure regulator assembly with O-ring. Inspect filter screen for contamination. If contaminated, remove and discard.

Fuel pressure regulator removal/installation (2.2L SFI engine)

To Install:

1. Apply clean engine oil to the new pressure regulator O-ring and install the O-ring on the regulator.
2. Install the regulator on the fuel rail. Apply thread-locker to the mounting screw.
   • Tighten the screw to 106 lb in (12Nm).
3. Connect the negative battery cable.
4. Use the following procedure to pressurize the fuel system and check for leaks;
5. Turn the ignition ON for 2 seconds.
6. Turn the ignition OFF for 10 seconds.
7. Turn the ignition switch back ON to run the fuel pump again and pressurize the fuel system.
8. Check the fuel rail assembly for fuel leaks.

4.3L Engine RPO L35 To Remove:
4.3L (RPO L35) Fuel meter body assembly

1. Before servicing the vehicle, refer to the Cautions and Warnings in the beginning of this section
2. Remove or disconnect the following:
   • Upper intake manifold (See: Upper Intake Manifold)
   • Fuel pressure regulator retainer clip (M) and discard the clip
   • Regulator (N) from the housing by twisting and pulling the fuel pressure regulator (N) and using a shop towel to catch any spilled fuel
   • Regulator seal O-ring (R) and discard the O-ring seal
   • Regulator filter (Q) and discard the filter
   • Regulator seal O-ring (P) and discard the O-ring seal
   • Backup ring (O) and discard the ring
3. Cover the fuel pressure regulator housing to prevent contamination from entering the fuel system

To Install:
4.3L (RPO L35) Fuel meter body assembly

1. Lubricate the NEW O-ring seals with clean engine oil
2. Assemble the following new parts to the fuel pressure regulator:
   • Backup ring (O)
   • Regulator seal O-ring (P)
   • Regulator filter (Q)
   • Regulator seal O-ring (R)
3. Install or connect the following:
   • Fuel pressure regulator with the vacuum tube pointing down
   • Fuel pressure regulator retainer clip (M)
   • Upper manifold
4. Test drive the vehicle to confirm the repairs

RPO LU3 To Remove:
4.3L (RPO LU3) Fuel meter body assembly

1. Before servicing the vehicle, refer to the Cautions and Warnings in the beginning of this section
2. Remove or disconnect the following:
   • Upper intake manifold
   • Fuel pressure regulator retainer clip (E)
   • Regulator (F) from the housing by twisting and pulling the fuel pressure regulator (F) while using a shop towel to catch any spilled fuel
   • Regulator seal O-ring (J) and discard the O-ring seal
   • Regulator filter (I) and discard the filter
   • Regulator seal O-ring (H) and discard the seal
   • Backup ring (G) and discard the backup ring
3. Cover the fuel pressure regulator housing to prevent contamination from entering the fuel system

To Install:
4.3L (RPO LU3) Fuel meter body assembly

1. Lubricate the NEW O-ring seals with clean engine oil.
2. Assemble the following new parts to the fuel pressure regulator:
   • Backup ring (G)
   • Regulator seal O-ring (H)
   • Regulator filter (I)
   • Regulator seal O-ring (J)
3. Install or connect the following:
   • Fuel pressure regulator (F) with the vacuum tube pointing down
   • Fuel pressure regulator retainer clip (E)
   • Upper intake manifold
4. Test drive the vehicle to confirm the repairs

If you mean your fuel pressure regulator. It's located on the CSEFI injector assembly, the regulator is located under the air intake plenum on the back of the fuel meter body.
If the regulator is bad it may cause either a drop in fuel pressure or an increase in fuel pressure at the rail . A drop in fuel pressure, if severe enough, can cause bad or no idle condition, engine starving for fuel and etc.

If the regulator is causing excessive pressure it can cause fouled plugs, black smoke from exhaust and rough engine performance.
Before you change the regulator check for cracked, rotted or disconnected vacuum hose.

Also you can connect a fuel pressure gauge to the schrader valve on the rail and monitor the pressure to see if it is in specifications, or to see if the fuel pressure drops rapidly after engine shutdown.

Hope this helps and good luck with your project. Thank you for using Fixya

If you look at the top of the upper intake manifold plenum with the air intake duct work off you will see 2 shiny fuel tubes that feed into the fuel meter body. The fuel meter body also has an electrical connector right in the middle of it. The pressure regulator is mounted on the side of that body. You'll have to remove the upper intake manifold manifold to replace it. Before you do that, be sure to bleed the pressure off the fuel system.

its located under the upper intake plenum on the side of the injector metering block

if it has the central fuel injection, the regulator is on the metering
body under the intake pletium. auto parts gets about $45 dollars for it. you also need to replace gaskets as well.