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Fuel rail not holding pressure?

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Old Aug 10, 2004 | 02:49 PM
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Default Fuel rail not holding pressure?

While doing my Intake & gaskets I went to relieve the fuel pressure at the rail and
nothing?
Could it be the check valve in the fuel filter? If there is one?
Its been on since I bought the car two years ago as I was told it was just changed.
I soaked the injectors in 50/50 gas and fuel injection cleaner while doing the intake.
Does seem to have a little longer crank time at first start in morning.
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Old Aug 10, 2004 | 02:59 PM
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I know when I did my SC a while back, I didn't get much preassure out of the reail when I disconnected it. I think if the car isn't on, the fuel pupmp won't prime the lines up to preassure. Maybe someone else can verify this at all?
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Old Aug 10, 2004 | 03:44 PM
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Its normal to have it lose pressure given enough time. If its just leaking back into the fuel tank its not much of an issue but if its leaking from your injectors that could be a nasty problem. You can hook a fuel pressure gauge to the schrader (sp?) valve and check from there or if you don't have one the free version is as follows:

Raise the fuel rail a few inches above the manifold, injectors included, and turn the key on...*tada!*

Its a good idea to place a paper towel under the injectors. This helps keep anything from falling into the engine and also makes it easier to determine which injector may be leaking.
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Old Aug 10, 2004 | 06:26 PM
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Default rail

Never though of that. Could have done it when I installed the fuel rail today.
OH well.
Its definitly not holding pressure at all. If I get in the car and key it up then turn off
and check pressure there is none.
I don't think its leaking at the injectors, I just soaked them and the car starts right up no problem. If it were flooding fuel in the cylinders it would take a while to start and skip a little at first. I think.
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Old Aug 10, 2004 | 07:20 PM
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Bad fuel pressure regulator? Sounds likely to me.
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Old Aug 11, 2004 | 08:24 AM
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Default regulator

could I remove it from the rail and clean it out?
I heard they are expensive.
Maybe I'll try the 10 dollar filter first then the reg.
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Old Aug 11, 2004 | 06:53 PM
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There is a snap ring holding it in. You could try flushing it out, but normally the internal diaphram, or whatever is in there, has worn out with age. They're about $50 from GMPD.
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Old Aug 12, 2004 | 10:08 AM
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Default regulator

Thanks for the info.
What should I flush it out with? Don't wan't to ruin the diaph. worse with something like carb cleaner.
Maybe I should add fuel injector cleaner to the tank at next fill up and see if that cleans it out?
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Old Aug 12, 2004 | 10:28 AM
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Originally Posted by SSEi95
I know when I did my SC a while back, I didn't get much preassure out of the reail when I disconnected it. I think if the car isn't on, the fuel pupmp won't prime the lines up to preassure. Maybe someone else can verify this at all?
that happends with me also
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Old Aug 13, 2004 | 09:23 AM
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Default pressure

So we have more than a few cars out there that are not holding pressure.
I think there is also a check valve in the fuel pump according to my book.
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