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Fuel Pressure Regulator?

Daboss

By Daboss,
in Engines & Forced Induction

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Daboss Experienced

Daboss

Posted
Posted

Hey forum just need a question answered by people who are more experienced than me. Can fuel pressure be raised with an adjustable fpr if you maintain the stock fpr but have it blocked off from the vaccumm/boost line? Do you have to get the fuel rail adapter in order to raise fuel pressure with the adjustable fpr or just tee the stock boost/vaccumm line to the boost/ vaccumm line of the adjustable fpr? So in short the stock fpr is still attached to the fuel rail just that the boost/vaccumm line has been removed and the port for it blocked while an adjustable has been placed on the fuel rail using the vaccumm/boost line that the stock fpr used will pressure be increased if adjusted by the fpr or does the vaccumm line have to be tied into the stock regulator. Thanks in advance for all help. What am thinking is that since the stock regulator is still on the fuel rail that stock pressure will be maintained no matter what but with the adjustable attached you can raise the pressure as desired but cannot lower it from stock because of the stock regulator. Am I right for thinking this?

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https://www.sau.com.au/forums/topic/187623-fuel-pressure-regulator/
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Daboss Experienced

Daboss

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Posted
oh man, paragraphs man, paragraphs. can you edit it just a touch?
Try again mate

Lol. Ok my bad in short I want to know if you have an adjustable fpr installed and maintain the stock fpr do you have to tee the stock fpr in, in order to raise pressure or just block it off somehow? Also does this mean that the fuel pressure cannot be adjusted below stock with the adjustable fpr since the stock regulator is still attached to the fuel rail?

dangerman4 Mentor

dangerman4

Posted
Posted

you just answered your own question.

if you are still running the stock fpr then its standard setting is the lowest pressure you can possibly achieve.

but my question to you is if you were to install a aftermarket fpr it would only be to raise fuel pressure.

so why would you be worried about lowering the fuel pressure below standard?

the money you spend on a new aftermarket fpr you should spend on a 044 intank and just run the standard fpr up to around 400rwkws.

WogsRus Veteran

WogsRus

Posted
Posted (edited)

yess YOU CAN keep the stok one in line with the adjustable one.

The stock FPR does a good job at keeping the fuel pressure from fluctuating as it is damped, don't ask me how but it is.

The way to connect the FPR is, fuel in -> fuel rail -> stock reg -> fuel out -> adjustable reg -> fuel to return.

You NEED to run a vac line to all the regulators, otherwise at idle the stock reg, if vacume diconnected will run ritch as it will not see any vacumme, and at high rpm, the adjustable fuel reg will have to work harder as the stock one will not see any boost.

Then simply set the adjujstable fuel reg, obviously can't go below stock reg pressure. Seing as we are dealing with pressures and the overall fuel pressure will be set by the fuel reg with the highest preset pressure, in our case the adjujstable reg.

Hope that helps.

Edited by WogsRus
BezerkR32 Veteran

BezerkR32

Posted
Posted

Had a customer car come in that had an after market reg fitted with the stock one still in place. the stock reg failed and closed, causing an injector o ring to get squeezed out which caused a massive internal fuel leak that hydraulic locked the engine. so remove the standard reg with a saard adapter for $30. Most tuners prefer them removed also.

yess YOU CAN keep the stok one in line with the adjustable one.

The stock FPR does a good job at keeping the fuel pressure from fluctuating as it is damped, don't ask me how but it is.

The way to connect the FPR is, fuel in -> fuel rail -> stock reg -> fuel out -> adjustable reg -> fuel to return.

You NEED to run a vac line to all the regulators, otherwise at idle the stock reg, if vacume diconnected will run ritch as it will not see any vacumme, and at high rpm, the adjustable fuel reg will have to work harder as the stock one will not see any boost.

Then simply set the adjujstable fuel reg, obviously can't go below stock reg pressure. Seing as we are dealing with pressures and the overall fuel pressure will be set by the fuel reg with the highest preset pressure, in our case the adjujstable reg.

Hope that helps.

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