Originally Posted by ThunderFox (Post 1403312)

Your problem is easier to solve than you would think. Just add a fuel pressure regulator inline, with the return pipe connected to the return line and the outlet pipe connected to the returnless fuel rail. That way you're basically putting the fuel return where the original one is instead of next to the fuel tank. That's basically what the returnless system is: It has a constant pressure FPR next to the tank and a short return line.

Originally Posted by ThunderFox (Post 1403333)

To do so will require an adapter where you mount it. In fact there should be a "tee" sort of fitting with an inline "damper" that resembles an FPR in an NB. You may be able to use/modify that.

But to be fair, just getting an aftermarket one will work fine. Standard pressure should be near 3.0 BAR if you will use pressure reference, otherwise 3.5 BAR is good. This works, from experience with other cars with returnless systems, not the MX5 in particular.

Originally Posted by albumleaf (Post 1403398)

Man, if only someone had put all that information in a thread somewhere.

(I'll be a little helpful and tell you just to ditch the 03 alternator and go with a NA8 instead. Why bother?)

Originally Posted by c.v.r (Post 1403411)

Ofcourse I've read the entire thread. It said that you can keep the OEM pigtails of the guage sender and and CLT sensor, but the plug where these 2 meet, the 6 pin plug on the intake obviousely differs from the 8 pin connector on the NB harnass.
So which plug do I use then ?
Thank you for the advice on the alternator though.

Originally Posted by wackbards (Post 1403424)

I think you're describing the injector harness? IIRC, it has the CLT sensors in it. The 1.6 was batch injection, whereas the 1.8 is sequential. 2 extra wires...

Read this thread a couple more times.

Originally Posted by c.v.r (Post 1403310)

I've read in the 1.8 swap guide from flying miata that if you go standalone you do not need to swap the fuelrails. and thus you have to convert to a non return style fuel system. What will be the best solution since I have the pnp pro for the 90-93 chassis and that the fuel rail is extremely hard to find where I live.

Originally Posted by ThunderFox (Post 1403312)

Your problem is easier to solve than you would think. Just add a fuel pressure regulator inline, with the return pipe connected to the return line and the outlet pipe connected to the returnless fuel rail. That way you're basically putting the fuel return where the original one is instead of next to the fuel tank. That's basically what the returnless system is: It has a constant pressure FPR next to the tank and a short return line.

Originally Posted by c.v.r (Post 1403331)

Do I use the 90-93 FPR for this? isfo where do I mount it?

Originally Posted by ThunderFox (Post 1403333)

To do so will require an adapter where you mount it. In fact there should be a "tee" sort of fitting with an inline "damper" that resembles an FPR in an NB. You may be able to use/modify that.

But to be fair, just getting an aftermarket one will work fine. Standard pressure should be near 3.0 BAR if you will use pressure reference, otherwise 3.5 BAR is good. This works, from experience with other cars with returnless systems, not the MX5 in particular.

Originally Posted by c.v.r (Post 1403334)

I think I will be trying to find a rail and use the 90-93 regulator. Finaly found one pretty close to me.
Posted just now lucky me :D Thank you for the amazing help though.

Originally Posted by MX5RACER (Post 1403338)

On my car, I tapped the fuel rail where the regulator bolts to it, then used an A/N line to an aftermarket adjustable regulator.

Originally Posted by c.v.r (Post 1403393)

I will be rewiring the alternator so the ecu(pnppro) can regulate the voltage (I'm using the 03 alternator).

Originally Posted by c.v.r (Post 1403411)

Ofcourse I've read the entire thread. It said that you can keep the OEM pigtails of the guage sender and and CLT sensor, but the plug where these 2 meet, the 6 pin plug on the intake obviousely differs from the 8 pin connector on the NB harnass.
So which plug do I use then ?.

Originally Posted by Savington (Post 1403453)

So many bad posts in my good thread.



You cannot use your 1.6L or early 1.8L fuel rail on the later 1.8L engine. I doubt the FM guide actually says this, because FM is a good shop and would not give such bad advice. If they did actually tell you to use your 90-97 fuel rail on a 99-05 motor, they are wrong and you should not do that.



Suggesting that the OP convert his return-style car to returnless is a terrible idea. He would have to purchase an expensive aftermarket regulator as well as all of the fittings to connect this regulator. He would also end up with an inferior setup because he wouldn't have 2/3rds of the OEM NB fuel pulse dampers which make that system work. Please don't suggest this anymore. The OP should do what I recommend, which is buy a 99-00 fuel rail and use his existing regulator turned upside-down. In fact, the OP is probably in Europe based on his diction, so if he buys a used 99-00 rail from a breaker, it might even come with the proper NB1 return-style FPR, which is an even better idea which is also covered in the original post.



Yes, use your 90-93 FPR, mount it upside down, just like the first post in this thread says to. Please ignore ThunderFox.



No, no, no, please stop.



Good.



You can tap, but I would be a little sketched out by the thickness of the rail. There are very inexpensive FPR adapters available which will bolt into place and give you a 1/8" NPT port to work with.



Don't do this. You are just making your life needlessly harder.



Read the thread again. You don't need to swap anything. You use your original injector wiring. If you want sequential fuel, you will modify your original wiring. The NB wiring you posted a photo of belongs in the trash can.



Neither. You throw that away and use your original wiring. If you want sequential fuel, you will modify your original wiring. Trying to splice in the NB injector harness will go very badly for you.

:party:

Originally Posted by Savington (Post 1403453)

So many bad posts in my good thread.
You can tap, but I would be a little sketched out by the thickness of the rail. There are very inexpensive FPR adapters available which will bolt into place and give you a 1/8" NPT port to work with.

Originally Posted by c.v.r (Post 1403393)

I will be rewiring the alternator so the ecu(pnppro) can regulate the voltage (I'm using the 03 alternator).

Originally Posted by Savington (Post 1403453)

Don't do this. You are just making your life needlessly harder.

Originally Posted by Ben (Post 1403521)

Disagree. I love the ability to regulate voltage for many reasons including (1) potential for hotter spark when dwell limited (2) ability to increase or decrease voltage with load, as appropriate for application (3) ability to use over run conditions to charge battery

Originally Posted by Savington (Post 1403522)

Ben, can you clearly outline the wiring changes necessary for the thread? I'll add it to the OP if you can.