Introduction: 2004 VW Passat Fuel Pressure Regulator Replacement


Fuel injected cars are dependent on pressure in order to operate properly. The fuel pressure regulator is controlled by the vehicles vacuum and ensures that there is proper pressure at the injectors by venting excess fuel back to the tank. There are several systems that a vehicle with a malfunctioning fuel pressure regulator can display.

Clogged/Degraded spark plugs: To much fuel being injected into the engine will cause the spark plugs to clog and blacken.

Hard starting: A bad regulator can make a vehicle hard to start or start and stall shortly after. This usually occurs during the first ignition of the day or after the vehicle has sat for a period of time.

Rough idle: A bad regulator can starve the engine of gas while at idle causing to sputter while idling.

Black smoke: Low fuel pressure will cause excess fuel and oil to enter the engine, and some oil will leak from the tail pipe.

Smelling fuel in the oil: Low pressure can cause fuel to leak into the oil, if the dipstick smells like gas it could be a bad fuel pressure regulator.


Gasoline is highly flammable and extreme caution should be taken when working on any part of a vehicles fuel system. Some precautions include keeping open flame or heat sources away from the vehicle and ensuring that the engine is cool to the touch before beginning this procedure. Additionally the poster of this instructable is not responsible for any damage to the vehicle or injury to personnel.

Step 1: Required Items

1. Needle nose pliers

2. Flat tip screwdriver

3. Small hose clamp

4. New fuel pressure regulator (Can be obtained from local auto parts store or ordered from various websites)

Step 2: Remove Vacuum Hose

On this vehicle the vacuum hose is clamped on with a single use hose clamp. Insert the screwdriver into the loop in the clamp and turn to expand and loosen clamp. After loosening the clamp pull vacuum hose off and remove the clamp.

Step 3: Remove Retainer Clip

Using needle nose pliers remove retainer clip from fuel pressure regulator.

Step 4: Remove Regulator


Remove regulator by pulling straight up. Inspect interior of the fuel pressure regulator housing to ensure there is no foreign debris and clean if necessary.

Step 5: Install New Regulator

Insert new regulator into housing ensuring that the vacuum port is pointing in the right direction. While applying pressure to the top of the regulator insert retainer clip.

Step 6: Connect Vacuum Hose

Place adjustable hose clamp onto vacuum hose, attach hose and tighten clamp.

Step 7: Test

Run the vehicle, if the symptoms you were having are gone then Congrats! you have successfully installed a new fuel pressure regulator.