Fueling Help on 1999 with return-style setup
 

I need some experienced help with my fuel system please.

I have a bone stock 1999 Miata 1.8 engine with the stock returnless fuel rail and stock red 1999 NB injectors in it.

My chassis is set up return style for a turbo setup. It has a stock NB fuel tank with a Holley hydramat in it and a walbro 255 fuel pump mounted externally. I have a return style fuel system set up with braided AN fuel lines, one going from the fuel pump to an aeromotive adjustable FPR and one plumbed back to the tank to come off the rail.

So here is my question, I have a killer turbo ready fuel system on my chassis that I want to keep in place since I’ll be going turbo in a few months. But for now, I need to get this fuel system to work with a stock 1999 NB engine and ECU. What changes do I need to make?

I have a 1997 NB on-rail fpr (pictured installed) I can run that will make a way to connect the fuel return line back to the tank.

Can I just get a JDM BP5A ECU to account for the return style fuel system and call it a day? Or am I missing something? Thanks in advance.


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Set the FPR to the NB base fuel pressure and don't connect the pressure reference from the IM.

What Ted said. That base pressure would be approximately 58 psig.

That I can handle. Thanks for the confirmation. I ordered a JDM BP5A ECU today and some AN8 to 5/16 barb adapters so hopefully I can set it to 60 psi and have it be happy.