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Testing fuel pressure regulator

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Old 09-08-2008, 04:36 PM
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AssocRacer
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Default Testing fuel pressure regulator

Might have a bad regulator, was told to take the return line off of the fuel pump assembly and clamp it off. Then put a fuel pressure gauge on the schrader valve on the fuel rail and test fuel pressure. If it doesn't maintain pressure then regulator is bad. Is this true? Also, if this is true do i replace the regulator, diaphram and spring, or both?
Old 09-11-2008, 10:13 AM
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any suggestions/comments?
Old 09-11-2008, 10:16 AM
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Mekanic
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put a gauge on the schrader valve, check pressure with the rails primed, engine off, engine on with vacuum attached, engine on with vacuum off.

Smell the vacuum line, see if it has any fuel in it.

If you see more than 43psi your reg is bad
Old 09-11-2008, 10:18 AM
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Originally Posted by Mekanic
put a gauge on the schrader valve, check pressure with the rails primed, engine off, engine on with vacuum attached, engine on with vacuum off.

Smell the vacuum line, see if it has any fuel in it.

If you see more than 43psi your reg is bad
Right now the problem that i'm having is a lean condition, like there isn't enough fuel pressure, not too much. What vaccum line do i disconnect?
Old 09-11-2008, 12:35 PM
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aklim
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Originally Posted by AssocRacer
Right now the problem that i'm having is a lean condition, like there isn't enough fuel pressure, not too much. What vaccum line do i disconnect?
You want to disconnect the one leading to the FPR. That gives the FPR a "WOT" vacuum signal so you know what the max pressure is.
Old 09-11-2008, 12:47 PM
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low fuel pressure I would look at the pump/filter
Old 09-11-2008, 10:32 PM
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already replaced the pump, tech said that the check valve was bad.... but the problem didn't go away.

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