The Definitive "VVT swap into 90-97 chassis" Megathread.
#381
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.
#382
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.
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.
#383
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.
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.
Posted just now lucky me Thank you for the amazing help though.
#385
Wich part of the wiring do I use?
I'm currently in the swap process for a vvt engine, both engines are out (91 1.6, 03 1.8 vvt). I am going through the thread and following what needs to be done on the wiring side. I will be rewiring the alternator so the ecu(pnppro) can regulate the voltage (I'm using the 03 alternator). On this I need to do some more research on how to do that. For the rest of electrical stuff: What do I need to swap? the pigtails of the sensors or the engine harness in general that has the injectors and coolent temp sensors in it ?
the engine loom from the vvt motor
Very kind regards,
Cedric
Very kind regards,
Cedric
#387
So which plug do I use then ?
Thank you for the advice on the alternator though.
#388
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.
So which plug do I use then ?
Thank you for the advice on the alternator though.
Read this thread a couple more times.
#390
Thread Starter
Former Vendor
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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.
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.
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.
Yes, use your 90-93 FPR, mount it upside down, just like the first post in this thread says to. Please ignore ThunderFox.
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.
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.
For the rest of electrical stuff: What do I need to swap? the pigtails of the sensors or the engine harness in general that has the injectors and coolent temp sensors in it ?
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 ?.
So which plug do I use then ?.
#391
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.
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.
Holy **** you're amazing. I got all the solutions now on with the build
I completely understand why everyone suggests you when it comes to miatas, especialy this topic.
GOD!!!
#392
I forgot to mention in my post, it depends on which rail you get. I have seen three different factory rails on NB engines, the NB1, the NB2 and a JDM NB2. I believe it was the NB1 rail that had the most material and I felt very comfortable tapping it. I had previously used an adaptor plate and had the o-rings fail several times at Sebring in the middle of a track day in July heat! Knock on wood, it has been two years running the tapped fuel rail and no issues so far.
#395
The plate that I used had a cut out for the O-Ring to sit into, the factory FPR had an extension that the O-ring was inserted into the fuel rail on.
The first failure I had was the O-ring, the second was caused when one of the bolts backed out a bit. At the time the this was the only plate I could find locally.
The first failure I had was the O-ring, the second was caused when one of the bolts backed out a bit. At the time the this was the only plate I could find locally.
#400
-David