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What should the Fuel Pressure Be?

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Old Oct 10, 2015 | 05:31 PM
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Question What should the Fuel Pressure Be?

Trying to track down a P0174 code and I see no obvious signs of vacuum leaks,etc. I'm going to smoke it in a few days just to be sure I'm not missing something.

I hooked up the FP Gauge and here's what I am getting....

Ignition on,engine off 38 psi
Ignition on, car idiling 32 psi
ignition on,car idling,popping the throttle 38 psi

Does these look ok or are they too low?
Car is stock with 1k miles on new engine. The code went away for a month and then came back,nothing was done in that time.
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Old Oct 11, 2015 | 03:59 PM
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What is the stock specification.
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Old Oct 12, 2015 | 11:58 AM
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If you're still on the stock fuel system you should be at 58psi all day.
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Old Oct 12, 2015 | 02:05 PM
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yep,stock fuel system.
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Old Oct 13, 2015 | 09:38 PM
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58psi is for LS1's...
If it's an LT1 it should have 43psi with the vac line disconnected from the regulator.

The idle vacuum will change the idle pressure.
With a stock cam, 32-35 at idle is close.
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Old Oct 14, 2015 | 08:55 AM
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It's a LT1. All stock,except for cai.
I'll remove the reg. vac line and see what happens.
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Old Oct 14, 2015 | 04:28 PM
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Around 42-43 psi with Regulator vacuum hose removed.
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