FPR? is there supposed to be a line on it?

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Oct 21, 2011 | 05:55 AM

Phoenix64

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From: Alabama

FPR? is there supposed to be a line on it?

I'm used to FPR's having a vacum line on it. why is there nothing connected to the FPR's vacum port?

Oct 21, 2011 | 06:34 AM

MeentSS02

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From: Dayton, OH

Because he/she didn't want it vacuum referenced? I have the vacuum port plugged on mine since I wanted steady pressure throughout the MAP range.

Oct 21, 2011 | 02:33 PM

Phoenix64

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From: Alabama

So there is supposed to be one?
Where does it come from?
How does it get a vacum reference all the way back at the fuel tank?

Oct 21, 2011 | 03:52 PM

MeentSS02

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From: Dayton, OH

What are you working on? I have no idea what you are even looking at, so I'm not even sure where to start.

Oct 22, 2011 | 07:49 AM

Ollie8974

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No the stock regulator in the tank does not have a vacuum line on it.

Oct 23, 2011 | 03:07 PM

Phoenix64

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From: Alabama

Its just the 1998 formula with the stock system.

Oct 23, 2011 | 05:07 PM

slowpoke96z28

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From: cedar hill, tx

Quote:

Originally Posted by Phoenix64

So there is supposed to be one?
Where does it come from?
How does it get a vacum reference all the way back at the fuel tank?

it doesnt need a vacuum reference. this system is constant pressure, variable pulse width. what you see on the fuel rail is actually a little shock absorber to prevent crazy pressure fluctuations from immediate load changes.

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Oct 24, 2011 | 09:58 PM

joecar

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From: So.Cal.

The PCM knows the manifold absolute pressure and so looks up the correct IFR (since injector flow rate depends on the the squareroot of pressure differential between injector top and bottom).

If you connect that hose, you will have to modify the IFR table (make it flat), but you might have other problems due to the excessive length of small diameter hose.