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Fuel 20psi fuel pressure

  • Thread starter Thread starter Case4
  • Start date Start date Feb 15, 2024
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    20 psi fuel pressure backfiring thru intake
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Case4

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#1
  • Feb 15, 2024
  • #1
Hey guys I'm sorry to keep asking for advice but I'm at a loss, I've got a 92 g.t and it's backfiring thru the intake, when it does this it bucks, I've changed fuel pressure regulator, fuel filter, pump seems to be working properly, relays good, replaced TPS, and IACV as well, the car still runs on 20 psi but has crappy power, what else could this be, I'm beating my head in here, thanks.
 

General karthief

wonder how much it would cost to ship you a pair
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#2
  • Feb 15, 2024
  • #2
Case4 said:
pump seems to be working properly, relays good, replaced TPS, and IACV as well, the car still runs on 20 psi but has crappy power,
Click to expand...
Well it will run if you shoot gas into the intake with a squirt gun too, the tell here is the 20psi fuel pressure, change the pump, inspect the fuel lines under the car, sometimes errant placement of a jack or jack stand has been known to deform fuel lines.
think of it this way, fuel, like electricity is measured, anything less than the working pressure/volts will still work, just not nearly as well.
 
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JD1964

there is enough sticking out to grab on to
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#3
  • Feb 15, 2024
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There’s a short section of rubber hose on the fuel pump assembly in the tank. It connects the line on the sending unit to the pump. This hose commonly ruptures. When it does the pressure at the fuel rail can’t rise to the spec because the fuel is just blowing out of the ruptured hose inside of the tank. It happened to my 92 a few years back. If you want to check it out you have to pull the tank. Thing is, once you’re in that far you replace the pump anyway.
 
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JD1964

there is enough sticking out to grab on to
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#4
  • Feb 15, 2024
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By the way I think my hose was old and weak to begin with. However, I think it ruptured when the alignment mechanic had pushed my return line out of his way when doing the alignment. This kinked the return line. Without a path for the fuel to return to the tank, the pressure spiked and blew the hose.
 

JD1964

there is enough sticking out to grab on to
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#5
  • Feb 15, 2024
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Case4 said:
, pump seems to be working properly,
Click to expand...
It’s kinda unclear the way you wrote this. Did you pull the tank and replace the pump and small hose section?
 

Mustang5L5

That is…until I whipped out my Bissell
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Have you actually dropped the tank?

Split hose on the fuel pump would be my assumption based on what you said
 
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Case4

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Mustang5L5 said:
Have you actually dropped the tank?

Split hose on the fuel pump would be my assumption based on what you said
Click to expand...
No not yet
 

FastDriver

I was uncomfortably high & wearing a helmet
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#8
  • Feb 21, 2024
  • #8
Just bought a nice new Walbro GSS340 (255 LPH pump) for like $80. Just buy a pump and get in there, bud.
 
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