Fuel pump or regulator

[Checkingfirst]

When i turn key on / eng off, i get fuel pressure up to 61 psi but it drops right back off to 0 psi. I can start car if quick befor drops and pressure is fine when running. Is this a pump problem or regulator problem on 2000 bravada. Please help.

[jd-autotech]

if the regulator is bad you pull off the vac hose going to the regulator and if there is any gas present even a drop then the regulator is bad but that will usually cause the car to have an extended crank time before starting i would thnk the pump is your problem before the regulator, is your engine light on or anything else we should know?

[Chris Stewart]

Where is the fuel pressure regulator on a 2000 4.3 SCPI?
I have a 2000 S10 I can check.
Thanks

[Checkingfirst]

I can’t pull the vacuum hose off as the regulator is internal in the intake manifold and I’m hoping not to have to pull it apart if problem is in pump. The engine light comes on when key is turned on but goes off when started. Problem is lost of pressure when pump kicks off. Not sure if draining trough regulator back into tank or backflow trough pump. Leaning towards replacing pump. Any advice on brand to install or avoid.

[Chris Stewart]

The most cool Pros here recommend the AC Delco only.

[old_master]

The fuel pressure regulator is inside the plenum and does NOT have a vacuum line connected to it. The port on the regulator is exposed to manifold absolute pressure and doesn't need a vacuum line.

Key on, engine off, pump running, pressure must be 60psi to 66psi and remain above 55psi for 3 to 5 minutes after the pump shuts off. Pressure dropping to zero, as mentioned above, is most likely the check valve in the fuel pump. The only way to tell for certain is to connect the pressure tester directly to the pressure line at the fuel filter. Activate the fuel pump and pressure should be 73psi to 108psi and must remain above 55psi, (probably be closer to 70psi) for 3 to 5 minutes after the pump shuts off.