Fuel pressure regulators for these cars are getting harder to find.  The '77 and earlier EFI cars use a different design, with two regulated fuel inlets, that remains somewhat available.  But I can't find the single-inlet version for the '78-83 cars anywhere.  I'm looking because I'm considering an aftermarket fuel rail for my '77, which would eliminate the need for the dual-inlet type.  The usual sources I'm familiar with are out of stock for the later FPR.  Some owners have retrofitted aftermarket adjustable FPRs.  But only a couple use vacuum reference like OEM.  Also, most aftermarket FPRs only go down to 3.0 bar (OEM are 2.5 bar).  And they leak down during shutoff, making starting prolonged and aggravating.  I figure you '78 and ZX guys would have seen this sooner, and may have found a fix.  TIA.

Edited September 27, 20231 yr by the_tool_man
Corrected "outlet" to "inlet"

@HusseinHolland had some posts about the same problem.  In the past I had modified an adjustable regulator to be vacuum modulated.  Made me get on to Rockauto and look around.  VW's Super Beetles had 2.5 bar EFI in the seventies.  The FPR's are cheaper than the Nissan versions.  Should be able to make it work.

https://www.rockauto.com/en/catalog/volkswagen,1978,super+beetle,1.6l+h4,1423178,fuel+&+air,fuel+injection+pressure+regulator,6124

1 hour ago, Zed Head said:

@HusseinHolland had some posts about the same problem.  In the past I had modified an adjustable regulator to be vacuum modulated.  Made me get on to Rockauto and look around.  VW's Super Beetles had 2.5 bar EFI in the seventies.  The FPR's are cheaper than the Nissan versions.  Should be able to make it work.

https://www.rockauto.com/en/catalog/volkswagen,1978,super+beetle,1.6l+h4,1423178,fuel+&+air,fuel+injection+pressure+regulator,6124

Thanks Zed Head.  That part number looks promising.  And it seems to be widely available, too.

I'd read your thread about alternatives that @HusseinHollandreplied to.  But that evolved into temp sensors and fuel curves; way above my head.  I was hoping that as "hard to find" became NLA, someone would forge ahead with a workable solution, whether that be an FPR from a motorcycle, or some other part(s) that had been shown to work.

Volvo also used a 2.5bar reg on several models (1983 240 2.3l - about $50 on Rockauto)- one version has a barb return line, but uses a flare fitting for the feed. I don't know what Datsun did on the later 280's. Is it identical to the beetle version?

 

Here's 78.  The barbs are different but the orientation is about right.  The ZX looks about the same I think the mounting bracket might be slightly different.  I found an eBay FPR that is slightly different.  Says it's for the ZX's.

https://www.ebay.com/itm/304857213677?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=-EOJC1W2RHK&sssrc=2047675&ssuid=bBzFtXzvTQO&widget_ver=artemis&media=COPY

1980

Here's a 76, for the three piece rail, just to round things out.  A person could insert a T fitting and hang the FPR off of it in a pinch.

If I did my research right, the Toyota Celica Supra & Cressida FPRs should operate around the correct pressure.

I was thinking that with the female threaded end you could possibly find a barb that would allow you to connect it to the fuel rail with a short piece of hose.

Has anybody ever looked at this Beck/Arnley 158-0073? https://www.amazon.com/Beck-Arnley-158-0073-Injection-Pressure/dp/B000CB03EA

It came up in a search for L-jetronic fuel pressure regulator. I haven't drilled down enough to see if the specs are available.

1 hour ago, SteveJ said:

Has anybody ever looked at this Beck/Arnley 158-0073? https://www.amazon.com/Beck-Arnley-158-0073-Injection-Pressure/dp/B000CB03EA

It came up in a search for L-jetronic fuel pressure regulator. I haven't drilled down enough to see if the specs are available.

I was wondering about that one myself.  It turns out the one Zed Head linked on Rock Auto (post #2 above) crosses to that same part number.

Edited September 27, 20231 yr by the_tool_man
Added note to which post I referenced.

1 hour ago, SteveJ said:

If I did my research right, the Toyota Celica Supra & Cressida FPRs should operate around the correct pressure.

I was thinking that with the female threaded end you could possibly find a barb that would allow you to connect it to the fuel rail with a short piece of hose.

I looked up some other images without the plug in the female thread.  It does look like a pipe thread, so probably JIS, which is interchangeable with BSP threads.  Finding a hose barb, or even an adapter to thread it onto the end of an extruded fuel rail should be no problem.  The unanswered question is what the pressure rating for this FPR is.  I tried to look up the specs, and even found a table to cross-reference a dozen equivalents.  But none of them go beyond listing what cars they're a direct fit for.  EDIT: After some more digging on Toyota forums using the OEM part number, I'm seeing the expected fuel pressure at idle around 36psi, which is correct for our cars.

Edited September 27, 20231 yr by the_tool_man
Added more info

The VW part has two flared nipples, for rubber hose and clamps.  The male threads are for fastening to a mounting bracket.  The adjustable Bosch FPR that I had used the same design.  I think that I modified an old broken Nissan FPR and used its bracket to mount the Bosch.

The 37 psi shown as the spec. is almost certainly a typo.  The Beck Arnley piece is in the same list of VW FPR's.  Circling back...

https://www.rockauto.com/en/catalog/volkswagen,1978,super+beetle,1.6l+h4,1423178,fuel+&+air,fuel+injection+pressure+regulator,6124

These reviewers on Amazon use the Standard PR134 on BMW motorcycles.  Up to 1990.  Who knew.

https://www.amazon.com/Standard-Motor-Products-PR134-Regulator/dp/B000C7YAJ8#customerReviews