Why would a fuel pressure regulator completely block the flow of fuel into the fuel bar?

Tiny
SQRTFRME
  • MEMBER
  • 2000 VOLVO V40
  • 150,000 MILES
Why would a fuel pressure regulator completely block the flow of fuel into the fuel bar like the pump works it pressurizes all the way up to the fuel pressure regulator I've replaced the fuel pressure regulator twice and I still am getting no gas past the fuel pressure regulator.
Wednesday, September 25th, 2024 AT 12:00 PM

10 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

That honestly doesn't make sense. I understand your confusion. If you have pressure to the regulator, try applying vacuum to the regulator to see if the fuel moves through it.

If that doesn't change anything, remove the regulator from the engine, connect the fuel supply, and place the regulator into a container to catch fuel. Turn the key to the run position and see if fuel comes out of the regulator. If it does, something in the fuel rail is stopping the fuel flow.

Try that and let me know what you find.

Joe
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Thursday, September 26th, 2024 AT 12:59 PM
Tiny
SQRTFRME
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So, we have removed the whole unit from the engine and when gas is applied to it, it still does nothing the fuel rail bar is clear all the way through to the end you can see with flashlight and has no relays attached to it when looking at up the unit I bought has a 48 PSI rating and the unit originally for my car has a 45 but that's a negligible difference and it really shouldn't be causing an entire stop in the fuel flow I am still at a loss.
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Thursday, September 26th, 2024 AT 1:25 PM
Tiny
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And we have applied vacuum and replaced the vacuum line to it as some places said that even a small hole could cause the whole unit too malfunction which I don't entirely understand either because on startup there's no vacuum really there to begin with once it's running I could understand the vacuum being necessary but just starting the car it should just be a squirt.
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Thursday, September 26th, 2024 AT 1:27 PM
Tiny
JACOBANDNICKOLAS
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Hi,

Is the quick connector original?

Joe
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Thursday, September 26th, 2024 AT 6:01 PM
Tiny
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Yes, but the new regulator insert isn't.
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Thursday, September 26th, 2024 AT 6:35 PM
Tiny
JACOBANDNICKOLAS
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Hi,

Is the new insert the same as the original one? Something has to be blocking or preventing the fuel from leaving the fuel line.

Joe
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Friday, September 27th, 2024 AT 7:11 PM
Tiny
SQRTFRME
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No it's not they sold me one with a 48 PSI the original is 45psi but that shouldn't be enough of a difference too entirely stop the flow.
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Friday, September 27th, 2024 AT 7:46 PM
Tiny
JACOBANDNICKOLAS
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I agree with you, but at this point, that seems to be the only possibility.

Joe
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Friday, September 27th, 2024 AT 7:55 PM
Tiny
SQRTFRME
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Well, I ordered another one that is supposed to be proper for the car at the 45 PSI I will let you know if that changes anything whenever it comes in.
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Friday, September 27th, 2024 AT 9:12 PM
Tiny
JACOBANDNICKOLAS
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Hi,

Thanks for the update. I look forward to hearing from you. I'm interested in knowing if that is the issue.

Take care,

Joe
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Saturday, September 28th, 2024 AT 6:23 PM

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