FPR project - cheaper, more available (for a while anyway)

[Zed Head]

I got reinterested in a thought I've had before about finding a way to use a more available FPR on the 280Z fuel rails, since the stock PFR's are becoming scarce.  I just looked on Rockauto and they don't even list FPR's as an option, not even an out-of-stock listing.

https://www.rockauto.com/en/catalog/nissan,1978,280z,2.8l+l6,1209260,fuel+&+air

I browsed around Rockauto and realized that the 2.5 bar (36.3 psi) pressure spec. was only around for a few years.  Then they went to 3.0 bar, or some odd spec like Ford used of 2.7 bar (why Ford, why?).

But I found a Bosch listing and cross-ref'ed it to Rockauto.  I don't have my tools available or I might try to build something but it looks pretty easy.  A small block of aluminum with a few holes in it should work, I think.

Just posting in case somebody wants to try it.  It might even be worth producing for sale.  

Here is the trail I followed.

https://electromotive.com/our-products/2-5-bar-rail-mount-fuel-pressure-regulator/

The Bosch number -

https://www.ebay.com/itm/275118121382

Rockauto using the Bosch number - 

https://www.rockauto.com/en/partsearch/?partnum=0280160225

[Zed Head]

Here's another option that only requires some hose adapters.  No luck on Rockauto though.  Spendy.

https://www.blackvlvparts.com/product/bosch-fuel-pressure-regulator-2-5-bar-7564131/

 

[Zed Head]

Here's the Walmart version.  Herko.  Never heard of them.  Actually doesn't look bad.  

https://www.walmart.com/ip/Herko-Fuel-Pressure-Regulator-PR4082-For-Renault-Fiat-Alfa-Romeo-78-89-2-5-Bar/855274203

https://herko.com/

[HusseinHolland]

Both of those types are common on Volvo 240 / 740 / 940 series, depending on year. There is a 2.5bar version of the first style (o-ring). The  o-ring fitting is the same dimensions as any composite injector, so a universal injector bung could be modded for use. The last one you posted was used on all Fiat/Bertone X1/9's with EFI - 1980-87.

There are FPR pods used on 90's Volvo (850, x70) & VAG models that has a removable FPR. Those you can buy Adjustable  FPR's for, which would allow changes depending on tuning & other mods.

I used one on my old Volvo converted to pickup truck when I +T'd it

Downside is you can't buy the pod - it comes with nitrile/nylon sheathed lines attached. I cut them off and/or cut them down & make my own lines

Gm also used this design FPR on LS motors - I know because the one I'm putting in my pickup truck has a housing that has the Bosch FPR. So there may be other options. 

I think using the 3 way Volvo style would work the best in terms of compatibility with the rail, since it has input, return & regulated output . I have another I scavenged from a parts car many years ago, so at some point I can test in on my '75 rail...

Edited April 14, 2023 by HusseinHolland

[Zed Head]

The first one looks very interesting because it's adjustable and has a vacuum reference port.

Do you have some internet links or part numbers?  I've found that many of the older parts that would be valuable for the Z's are not actually available anymore.  I built a vacuum reference adjustable FPR for my engine but now you can't get the FPR that I started with.  NLA.

[HusseinHolland]

9 hours ago, Zed Head said:

The first one looks very interesting because it's adjustable and has a vacuum reference port.

Do you have some internet links or part numbers?  I've found that many of the older parts that would be valuable for the Z's are not actually available anymore.  I built a vacuum reference adjustable FPR for my engine but now you can't get the FPR that I started with.  NLA.

The adjustable regulator is this one: EuroSpec Sport. The standard (non-adjustable 3bar) FPR in the 2nd pic is what all Volvos & VAG came with. The black plastic pod that it sits in is a separate part that was only sold with the feed & return lines attached, so pretty much the only way to get it is to cut it from a parts car.

 

The Volvo 3bar FPR is PN 9404583 for reference. They don't go bad, so if you were going to use one, I'd get it used.

EDIT - VAG # 037133035C  Bosch # 0 280 160 557

 

EDIT - this is an aftermarket housing that accepts that style FPR. I just found that searching, so there may be other (less expensive options)

 

This composite one for a Harley also accepts the same design FPR, don't know if the ports are useable

Edited April 14, 2023 by HusseinHolland

[Zed Head]

The other benefit of that first one is that it probably does not leak down when the pump is off.  The shiny anodized aluminum adjustable FPR's all seem to leak down because they use a ball and seat for the valve.

The holder that you linked for the Harleys seems to be a two exit port system like the 1978 and later regulators.  Looks like it would probably plumb in nicely on a 78 or later factory fuel rail.  

It took my brain a while to figure out how they worked when I first saw that style.  The valve is actually inside the FPR, probably the flat steel seat.  

https://www.denniskirk.com/v-twin-manufacturing/fuel-pressure-regulator-housing-63773.p1802126.prd/1802126.sku

https://www.ebay.com/itm/111963132346

[Zed Head]

The bike shops also sell the regulators.  Can't find specs though, yet.  Edit - Looks like they are three bar. 

(https://www.ebay.com/itm/222779941480)

https://www.denniskirk.com/search/fuel+pressure+regulator.q

https://www.amazon.com/Fuel-Pressure-Regulator-Davidson-1995-2001/dp/B07W7QM3SM

Edited April 14, 2023 by Zed Head

[HusseinHolland]

4 hours ago, Zed Head said:

The bike shops also sell the regulators.  Can't find specs though, yet.  Edit - Looks like they are three bar. 

(https://www.ebay.com/itm/222779941480)

https://www.denniskirk.com/search/fuel+pressure+regulator.q

https://www.amazon.com/Fuel-Pressure-Regulator-Davidson-1995-2001/dp/B07W7QM3SM

We need 2.5bar for the Z? The adjustable one doesn't drop below 3bar either. 

[HusseinHolland]

5 hours ago, Zed Head said:

The other benefit of that first one is that it probably does not leak down when the pump is off.  The shiny anodized aluminum adjustable FPR's all seem to leak down because they use a ball and seat for the valve.

The holder that you linked for the Harleys seems to be a two exit port system like the 1978 and later regulators.  Looks like it would probably plumb in nicely on a 78 or later factory fuel rail.  

It took my brain a while to figure out how they worked when I first saw that style.  The valve is actually inside the FPR, probably the flat steel seat.  

https://www.denniskirk.com/v-twin-manufacturing/fuel-pressure-regulator-housing-63773.p1802126.prd/1802126.sku

Trying to find a schematic - typically the bottom-most port is the return - the I/O are in line with each other in the larger housing, so that female side may take some sort of push fit line, I dunno.

EDIT - yeah the female is the inlet, looks like the have a designed filter pressed into that 

 

 

Edited April 15, 2023 by HusseinHolland

[Zed Head]

1 hour ago, HusseinHolland said:

We need 2.5bar for the Z? The adjustable one doesn't drop below 3bar either. 

The print on the actual part says 0 - 5.   But the eBay text does say 3 - 5.  Who knows.

[kickstand80]

Nissan Stanza FPR has very close specs to the 280zx

Edited April 15, 2023 by kickstand80