How to repair a fuel leak above the fuel pressure regulator

Fuel from the pressure regulator can't enter the intake manifold with out passing through the injector first. That means that if you have a leak in the inlet manifold you have a leaking injector.
A fuel pressure regulator is no more than a controlled leak. You test pressure on the fuel rail, if you have pressure you have fuel to the injectors.
The regulator controls that pressure by controlling the return flow to the fuel tank. You are in trouble when a pressure regulator does not flow (leak) fuel from the pressure (fuel rail) and return ports.
To test weather a injector is leaking you remove it from the inlet manifold and pressurize the injector.

Hi Raquel,here's a link to your fuel pressure regulator and how to replace. Repair Guides Gasoline Fuel Injection Fuel Pressure Regulator AutoZone com Here's a new pressure regulator. GP Sorensen Fuel Pressure Regulator 800 366 at AutoZone com

www.autozone.com make a free account and access the free repair guides.

1994 Chevrolet S10 Blazer 4.3L, Vin W Customer Concern: DTC 45 The spark plugs are black on both banks. Right bank plugs are damp. Removed the tuning valve and looked inside the plenum. Can see a washed/clean area on the right side. Fuel pressure is good, it holds when the pump stops. Tests/Procedures: 1. Remove the upper intake plenum cover and inspect for a fuel leak at the fuel pressure regulator.

2. Inspect the fuel pressure regulator and return lines and fittings at the left side of the plenum.

3 Replace the Central Multipoint Fuel Injection (CMFI) unit. Potential Causes: Leaking Fuel Line - One or more may have a problem.
Leaking Fuel Pressure Regulator
Tech Tips: The fuel pressure regulator may only leak at a cold or hot engine, only with vacuum applied, or only without vacuum applied. The leaking at the fuel lines and fittings have as often been the result of repairs as the initial cause of the problem. Handle the lines and fittings carefully. The fuel pressure regulator is a integral part of the Central Multi-port Fuel Injection (CMFI) unit. Any failure requires entire unit replacement.

If it acts like it is flooding while idling, but it runs fine on the road, it could be running too rich and flooding it out due to leaking injectors, bad fuel pressure regulator, or excessive fuel pressure.

I would start by replacing the Fuel Pressure Regulator since it doesn't cost as much as the injectors.
Check your fuel pressure using a Fuel Pressure Check Gauge to see if the fuel pressure regulator is maintaining the proper pressure.

Vacuum is attached to the Fuel Pressure Regulator to control system pressure. When the fuel pressure regulator is not functioning properly it causes the fuel pressure to be above normal operating pressure. This condition causes excess fuel to be injected causing a rich mixture that produces black smoke.

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Where is it leaking? If its at the fuel rail fuel pressure regulator you may need a new regulator if leaking on the metal part. If its leaking at the rail side its just the "O" ring. Relieve fuel pressure(push in valve under plastic cap right side beside alternator on rail. Remove the torx screw holding regulator bracket. Pry out and replace "O" ring, reassemble. If its not the regulator it may be a fuel injector, you need to remove the fuel rail and replace both the upper and lower injector "O" rings. This however needs the intake manifold removed to repair.

2001-02 Grand Cherokee The fuel filter/pressure regulator is mounted to the body above the rear axle and near the front of the fuel tank.

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Relieve the fuel system pressure.
3. Remove or disconnect the following:
   • Negative battery cable
   • Fuel supply, return and pressure lines
   • Mounting bolts
   • Fuel filter/pressure regulator
   To install:
   
4. Install or connect the following:
   • Fuel filter/pressure regulator to the body. Torque the bolts to 30 inch lbs. (3 Nm).
   • Fuel pressure, return and supply lines
   • Negative battery cable
5. Start the vehicle, check for leaks and repair if necessary.

You could have either an injector that is stuck open or a fuel pressure regulator that has developed a leak. A leaky injector will usually only leak fuel into one cylinder as it is located just above the intake valve in the lower part of the intake while a leaky fuel pressure regulator will leak fuel into the front end of the intake manifold [behind the throttle plates] and the fuel will acuumulate throughout the upper intake plenum. When a fuel pressure regulator develops a leak the fuel that is escaping from it flows through the small 1/8" diameter plastic vacuum line which goes from the top of the regulator to the intake manifold. Even a trace of fuel in this line means the regulator is bad. I've seen both leak items leak but probably replace 10 regulators leak for every one injector. Good luck, hope you find your problem!

Release fuel pressure by removing fuel pump relay and turning engine over to release pressure. Place a rag to catch any fuel under regulator Fuel pressure regulator has a locking clip pry clip off remove vacuum line pull regulator out with twisting motion,replace fuel pressure regulator install clip connect vacuum line install relay. Check for leaks,your done.

REPLACE FUEL PRESSURE REGULATOR AND ALL O-RINGS ON FUEL RAIL.REPLACE THE ENTIRE FUEL RAIL AND FUEL PRESSURE REGULATOR.IF FUEL RAIL IS LEAKING..