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OE 94 FPR - deleted PRC valve + BOOST - do I need a check valve?

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OE 94 FPR - deleted PRC valve + BOOST - do I need a check valve?

 
Old 04-15-2019, 02:15 PM
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Default OE 94 FPR - deleted PRC valve + BOOST - do I need a check valve?

Hey yall

Now that I have removed the PRC (pressure regulator control) valve, and am running significant boost, should I even be using the OE 94 FPR anymore? If I can still use it, do I need a check valve between the intake manifold and the regulator or is it okay for the OE regulator to see boost?

I was running boost with the PRC valve installed, and imagine the OE FPR was already seeing boost reference instead of vacuum reference. What would this do to my fuel pressure? I don't really know to well how the OE FPR works I guess..

Thanks
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Old 04-15-2019, 03:33 PM
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afm
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The PRC valve is just there to help prevent vapor lock. Many, many people run without it, and it is totally fine to let the NA manifold-referenced FPRs see boost. Any time other than a hot restart, the PRC valve is open, so your FPR was already seeing boost.

When you are in boost, the NA FPR raises the rail pressure at a 1:1 rate with MAP. This keeps differential pressure across the injector (and therefore flow per unit of pulse width) constant.

TLDR: don't install a check valve.
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Old 04-15-2019, 05:19 PM
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Poscat left. Thank afm! That was my suspicion, just wanted a confirmation and a better understanding of what the FPR was doing with MAP levels. Thanks again!
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