Skip the auto shop - Our mechanics make house calls

Q: No pressure after the FPR

asked by on

have a NA 1990 300zx that doesn't seem to be getting fuel past the fuel pressure regulator. I just bought a new pressure regulator and installed it in hopes that would fix the problem but it still doesn't have any pressure past the regulator. When I got the car just about all the rubber in the engine bay was dry rotted so I have replaced all the vaccum, fuel and water lines. I also did aiv, prvr and egr delete to simplify the engine. I have the vacuum line that goes to the FPR going to the plenum as instructed in multiple forums I have read for doing the aiv and prvr solenoid delete. Only thing I can think is that the plenum isn't creating enough vacuum to open the diaphram in the FPR but i dont know how to fix that. I can spray starter fluid in the plenum and the car will start up till it burns off the starter fluid just so you know.
My car has a manual transmission.

The fuel pressure regulator will regulate the fuel pressure by allowing fuel to return back to the fuel tank if the pressure gets too high. If the fuel pump never produces enough pressure and volume of fuel to run the engine, then you need to replace the fuel pump and filter. The vacuum line on the regulator should go direct to the intake behind the throttle plates to work correctly or you will get too high of a fuel pressure when the pump is working.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Stalling fuel pump flapper on 1994 Ford Probe

Hello. The fuel pump on your vehicle is powered through the fuel pump relay through direct battery power. The fuel pump itself is located in the fuel tank and there is not an access panel to easily change it. The...

Q: How do I connect an iPod to the sound system?

Your vehicle is designed for iPod connectivity. Connecting an iPod is easy: 1. Locate the iPod outlet connector, which is in the center console compartment. 2. Connect the specialized cable to the iPod outlet connector. 3. Connect the other end...

Q: The car will start and run on it's own with no key in the ignition.

Hi there. This issue is commonly caused by an ignition relay that is faulty. Essentially what happens is that the relay; which sends electricity to the starter relay to activate the starter, and the ignition system; is bypassing the signal...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...