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.

A: The fuel pressure regulator will regulate t...

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.

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・Save up to 30%

Get a quote

What others are asking

Q: Car hesitates, stalls at idle, P0102 code

Hello. This can be caused by a number of things. I usually install a scan tool first to see what the sensors are reading. Most of the time this is caused by a leaking intake manifold gasket. This is a...

Q: Vehicle whining after belt replacement

I would suspect another pulley the serpentine belt drives has a dry/loose bearing. I would recommend having a certified mechanic, like one from YourMechanic, take the belt back off and check each pulley for play and replace as necessary.

Q: Steering wheel stiff

Hello. If the wheel takes a lot of effort to turn, the power steering system is likely the problem. The power steering system includes the pump, rack and pinion, pressure and return lines. Your issue is likely due to a...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...