There should be no ambiguity or questions about the fuel system. It is not dependent on chassis or wiring or what intake manifold you use or anything else. For any NB motor in any NA chassis, you use a 99-00 rail and a USDM 90-93 -OR- EUDM 99-00 FPR.

Perfect, Thank you SAV.

Have a question on fitment of injector harness with squaretop and aftermarket fuel rail from Radium. The 97 injector harness appears much bulkier than NB injector harness that was designed to lay under the IM as opposed to above the fuel rail as the case in NA.
I have to take the squaretop apart to get to connect the injectors anyway..is there a recommended NB injector harness swap into NA?
Thanks

I used an NA8 FPR flipped on a BP4W rail with success for a while. It's a straight barb so no bending the tube.

KJ01-13-280

https://www.atkinsrotary.com/store/i...J01-13-280.jpg

Double post

No. The two harnesses are different enough that they are not interchangeable.

From the OP:

It may depend on which version of the 99-00 fuel rail you have, but the 94-97 FPR doesn't work in all cases. The 90-93 FPR does. If you want to avoid bending parts, use the EUDM 99-00 FPR which is designed for the application.

Oh wow, didn't know there where two different Bp4w fuel rails.

fuel rail
 

My injector can’t be turned 90 degrees due to clearance with the head. I guess will need to run it at 180 degrees and sneak the plug in the tight opening. Can someone confirm that they have also this much clearance with the squaretop.

The injectors were never oriented up like that, even from the factory.

I may have confused 97 with 99. On the NA8 they were straight by the head as there was more room between rail and head. Please correct me if I am wrong as i am a noob and being a bit OCD.

Coil wiring colors need to be edited. Ran into a no start issue because a 97 I was working on the colors did not match. Brown went to cylinders 2/3 and brown/yellow went to 1/4. Which also matches this thread

https://www.miataturbo.net/useful-sa...04/#post152397

https://www.miataturbo.net/attachmen...ine=1327066127

Done, thanks. Up to v1.06 now

Got a question, running a BP6D in a 96 chassis. Confirmed it has fuel/spark/compression. Loaded the 99-00 startup map from MSPNP.com MegaSquirtPNP by DIYAutoTune.com The vvt actuator is wired but not hooked up as we would like to get it started first. Using a stock oem 99-05 trigger wheel, that is installed correctly. Stock injectors, 99 fuel rail, 1.6 regulator, skunk2 intake. We were able to get the original motor running on the same ecu before pulling it.

Included data log and composite log.

Let me know what you think it is.

Just confirming. If I use the BP5B-13-280 (UK) fuel regulator, I should point the fuel return downwards correct? Seems like that makes it a convenient part. Thanks!

Yes, it fires down. You're basically using the EUDM parts in their original EUDM configuration.

On the S1 car I'm building (VVT motor into a '94), I used the VVT rail with an adapter and an external FPR. It is a tight fit, but it works. The adapter lets the outlet fire at a ~45deg aimed forward, which is the only space a fuel line would fit into. For folks who were going to use an aftermarket FPR anyway, it's a good option. I'll post some pics here and in my current S1/ST4 customer build thread later today.

Attachment 235546

This is our regulator adapter on a VVT fuel rail with an Earl's Vaporguard 1/8" NPT to 5/16" 90deg fitting. The green goo is Gasoila E85 sealant. There's no way to get a standard FPR in this spot with clearance for vac/fuel hookups, but you can get the NPT fitting oriented correctly so it just barely sneaks out of there. This is a good option for people who are going to run an aftermarket FPR (something like a Fuelab 545 would go inline between this and the return line) since you can use the OEM VVT rail that comes on the motor instead of sourcing a combination of US parts or a hard-to-find EUDM 99-00 setup.

Adapter: Trackspeed FPR Adapter

Fuelab 545-series: Fuelab Fuel Pressure Regulator

Can we add to the Alternator section of the first post that you need a different lug for the 94-97? It's easier to "relug/crimp new lug" it when you have the engine out.

Brown wire from engine harness (1.6) to 94 97 alternator. This app wont let me upload pics.