D-Jet Fuel Pressure Regulator, How high should it go? Options

[GregAmy]

What should be the maximum capability of the stock D-Jet pressure regulator? Mine only goes to 36.

If that's normal, is there another similar-format regulator that can go up to around 45psi?

Background: Microsquirt project. Was hoping to use the stock regulator, but now need something that I can easily mount in the same location, if possible. Injectors I'm using are rated at 43.5psi.

Discuss!

[GregAmy]

Quick update... per Summit Racing, MSD has discontinued the MSD-2220.

Rock Auto has the Delphi version, says it's 29psi.

I tried two used ones from Chris; one only got to 34psi, the other had the locking nut stuck so I didn't force it.

NAPA can get me a "FPR for the Porsche 914" but it's special-order only, and they don't know how adjustable it is.

Rock Auto looks like the Delphi version as well, 29psi listed.

I can't find a FPR for the car on Pelican's web site.

I'm guessing that if I'm running more than 35-36 psi I'll have to go aftermarket on the FPR...

[JamesM]

Didn't have time to tear into one this weekend but from the looks of the diagram im wondering if MSD didnt get to higher pressure via a longer adjustment screw. Would need to measure how much more could be added before the coils bind. From the drawing though I would think you should be able to dead head the pump with a long enough adjustment screw

Not sure when the last production run would have been, but guessing at 50 years old the OE springs may be getting a bit tired.

[JamesM]

Just did a bit more searching... this is an interesting read on the pressure regulator

https://www.thesamba.com/vw/forum/viewtopic...s+inside++fails

Cant tell for sure but it looks like the adjustment screw may be a custom part, so swapping may be out of the question. Also looks like new ones from anywhere may have gone NLA sometime over the last couple years and if that post is to be believed these have a high potential for wear that will affect every used one out there.

May be time to look at other options

[JamesM]

Knowing that 914 l-jet regulators are a direct swap (fitment wise) I started exploring what might be out there the the realm of cars that used similar systems.

914 L-jet regulators are non-adjustable, vacuum referenced and is supposed to give ~37-38 with zero vacuum. Those can still be had available new but isnt quite where we want to be...

Vanagon regulators are similar pressure wise


and then by some random luck i stumbled on this...

Bosch 0 280 160 256

vacuum referenced, 3 bar non adjustable. Would need an adapter on the inlet but other than that appears to be externally similar to a stock regulator.

https://www.amazon.com/gp/product/B00C818WG...45-cd78f07a84d8





This has some interesting candidates as well though i am not sure where they can be purchased. FPR 05-40 B (adjustable from 0.5 to 4 bar) and FPR 15-50 are of particular interest.

https://www.bosch-motorsport.com/media/down...minikatalog.pdf

[JamesM]

This is interesting. In the latest bosch catalog it looks like they only offer rail pressure regulators now, but they have an adapter to convert a rail regulator into an inline regulator...

https://www.bosch-motorsport.com/media/down...atalog_2020.pdf

http://www.bosch-motorsport.de/content/dow...abs=50227595-4/

May be more bad news for d-jet

[GregAmy]

May be more bad news for d-jet

Well crap.

I have not had a chance to digest all this in detail, but your bottom line appears to meet my experience over the last few days: the OE fuel pressure regulator is becoming scarce. One of my core reasons for developing a Microsquirt for myself was as a low-cost alternative to declining D-Jet parts (and tunability for mods); one of my design parameters was to do that with as few parts as possible. I was working under the ASSumption that the FPR was readily available new; that appears to be flawed.

Aftermarket adjustable "return/bypass" FPRs are common, but they won't fit into the stock bracket. I may have to rethink this paradigm and come up with something around an aftermarket part.

[JamesM]

May be more bad news for d-jet

Well crap.

I have not had a chance to digest all this in detail, but your bottom line appears to meet my experience over the last few days: the OE fuel pressure regulator is becoming scarce. One of my core reasons for developing a Microsquirt for myself was as a low-cost alternative to declining D-Jet parts (and tunability for mods); one of my design parameters was to do that with as few parts as possible. I was working under the ASSumption that the FPR was readily available new; that appears to be flawed.

Aftermarket adjustable "return/bypass" FPRs are common, but they won't fit into the stock bracket. I may have to rethink this paradigm and come up with something around an aftermarket part.

Your goals are the same that I had when I did my first install, only back then it was only the start of OEM d-jet parts supply drying up. Fuel pressure regulators going NLA is a fairly recent development though, from what I can tell sometime in the last couple of years. Its a bit of a surprise.

Take a good look at that part from the dub shop, i really think that may be the best bet. Using that 6AN to 5/16 barb bulkhead fitting it looks like it would mount in exactly the same way as a stock regulator, and the actual pressure regulator component is replaceable with modern Bosch of any pressure rating (or fully adjustable)

I think i may order one today just to play around with it.