PNP EMS Options for 97'

Hey guys. I'm looking at PNP EMS options for my 97'.

Here is the PM I originally sent to 18PSI on the Turbo Miata forum but I figured I should throw it out to the whole forum and see what people say.

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Originally Posted by Brap-Brap

Hey man, my name is Alec and i'm just a kid with a Miata who wants to have fun. I bought my first Miata, a red 97' 5-20-2017 but i've been messing with cars all of my life. I got it, changed all the fluids and spark plugs and wires and coils and now she's throwing misfire codes every time I get anywhere close to 6800 RPM. OBD-II just says "Random Misfire" and the CEL is starting to piss me off. I also want more power and full control of my car, so i'm looking into standalone ECU's. Didn't feel like posting a thread, but I did search some things on here to see what's what. I've been a lurker for some time and I know how serious you guys are about good products. I think I nearly pissed myself laughing over the many FFS "For F***s Sake" Supercharging flame threads with Tom the Yo-Yo master. But I would like to go to a standalone EMS and stay N/A for a while before I try going boosted. Keep in mind my car is my daily driver and at the end of the day I need to be able to open the garage door, hop in, turn the key and get going no matter if its 100 degrees in the middle of August or 0 degrees in January. I live in Ohio so emissions is not an issue.

The FM221 caught my eye. Keith has me hooked on things like cold-start, AC compensation, off-throttle fuel control and other stuff that seems nice for a daily.

But, I know how much you guys love Megasquirt (and for a good reason, its a damn good product) and so I wanted some advice. I was looking at the MS2PNP. (EDIT: MS3PNP also seems like an option... more down below...)

I've read this thread: https://www.miataturbo.net/hydra-58/...p-hydra-91029/

The ME guys just seem stupid, but FM are good people and I think they have the potential to make it a really great product.

The plan was get an AEM Wideband, GM IAT sensor, wire them up and delete the MAF.

What say you? MS2PNP (Again, MS3PNP, but see below) seems very popular but the options list of the FM221 looks nice.

Thanks.

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Yea there is a little brown-nosing I know...

Currently NA but I plan to go boosted in the future. Do I really need all the options of the MS3PNP or will MS2PNP suffice? What major advantages does MS3PNP have over MS2PNP other than things like "Rally-style anti-lag" and "3 step rev limiting"? I know it has 16x16 ignition map over the MS2PNP's 12x12 but what else is there? Is the FM221 a good product and do the extra options it offers really make a difference?

Thanks.

I would take your ECU project in 3 stages.

STAGE 1 - Get the car to run properly with the stock ECU.
You do not want to install an aftermarket control system then start tweaking the setting to compensate for a problem that is still there.
Some things to consider... Change the fuel filter, Change spark plugs to Denso 5304, Change air filter, replace the CAT, oil change to Mobil-1 15W-50, double check the spark plug wire/coil wiring locations, run premium fuel and check timing.

STAGE 2 - Select the aftermarket ECU brand that is supported by the seller and understands Miata's.
FM is a good choice for a seller. You may even want to change the front pulley for higher input resolution.
I would not buy a used system. An old system will quickly be obsolete by the time you are ready for your power conversions, has no support, and you have no idea what the previous owner did to it. Time, vibration, and corrosion are not your friend.
Tweak the setting to make the car run equal or better than stage 1.

STAGE 3 - Decide on your final power configuration. Your ECU is now ready to operate upon the first fire-up and ready for tweaking.

Fuel Filter is going in soon.

Plugs were literally just changed, in fact I changed them to try to fix the code but it's still popping up. Air filter has been changed. MAF cleaned. Crank Angle sensor will be checked soon. I just changed the oil to Mobil-1 10w30 with an M110 upgraded filter. Timing is advanced to 15 degrees and I only put 93 into it.

The thing still pulls hard (as hard as a Miata could) even when the CEL is flashing. Like 0 power loss or stuttering at all.

All signs point to the TSB released for 97's as a bad ECU with the PCM having a logic failure at high RPM. Only solution is a new ECU.

We'll see what happens.

A used '96 ECU will solve the '97 P0300 TSB.

MiataQuest is 100% correct.

As your DD and only car, adding a standalone ECU then going to turbo is not really the best move. If you can't solve the issue(s) on a stock car, how do you intend to solve them with the standalone ECU? That is bad logic on your part. Each modification you want to do has a degree of difficulty and learning curve. If you need the car to be available for work or everyday, you may want to invest in a beater car as a backup first.

Decided on MS over the FM unit as broader field of support and my local tuner is an MS specialist.

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Originally Posted by JamieH

A used '96 ECU will solve the '97 P0300 TSB.

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Not willing to put 20+ year old electronic part into my car. I cracked open a couple of junkyard ECU's I found from 90's and 00's cars and they all had leaking caps and cracked insulation on resistors, etc.

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Originally Posted by kung fu jesus

MiataQuest is 100% correct.

As your DD and only car, adding a standalone ECU then going to turbo is not really the best move. If you can't solve the issue(s) on a stock car, how do you intend to solve them with the standalone ECU? That is bad logic on your part. Each modification you want to do has a degree of difficulty and learning curve. If you need the car to be available for work or everyday, you may want to invest in a beater car as a backup first.

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What do I lose by going Standalone? It's worth it to me to spend a decent amount of money to equip the car with modern electronics that do a better job of diagnosing a problem than factory. A dedicated Knock sensor is better than the Crank Angle Sensor doing double duty. Also a IAT and MAP are more accurate than a MAF and with modern programming I can see what the engine is doing a lot better. Plus my issue only occurs at WOT and 6800+ RPM so if it really is a misfire i'll see it on the Dyno as that's what you tune... For the time being I could just not go WOT up to 6800 and have no CEL come up. But I want my revs dammit! And it won't be immediatly, I'm looking at options ahead of time so I don't waste time later on. I have a list of mods I want to do and I have familiarized myself with what each of them requires and the amount of time and effort I need to put into them to complete them. Standalone is as simple as plumbing a few things and plugging in and going. Spend a couple weekends tuning and maybe a dyno session and I'm good to go. Worst comes to worst I plug the original ECU back in and try again. Versus something like bushings, If I don't finish it that day well... You get the point.

Believe me I understand where you are coming from and normally I would agree its bad logic but at this point I have no idea what could be causing my issue. Code is P0300 and sometimes a P0303. Plugs were changed. Wires changed. Injectors checked and all good. Wiring to Injectors checked and all good. If I wasn't getting ignition it would throw a CEL for the cat and I would potentially be getting some backfiring. Also would be running rough. It's getting a proper amount of fuel because I bench tested all the injectors. Should I swap the 1 and 3 spark plug wires and see what happens (because wasted spark)? No clue what that will show except for a bad spark wire. No way the crank position sensor is bad it that would cause problems all through the rev range. Cam sensor is good as I was able to advance the timing to 15 degrees no problem. It was only after an oil change it started doing this. So i'll back the timing down to 10 degrees and see what happens. Doubt it'll do anything though.

I hope everything works out.
I have to agree with KFJ that having a daily beater car makes the Miata experience better.
It also keeps the Miata out of salt. I would hate to invest money into a car that is going to get rusty. Even worse, as it gets rusty it is terrible to work on.

Do you ever take your Miata on the Ohio 555 triple nickel just east of Columbus starting in Zanesville?
I do this every fall with the Columbus Audi group.
I can't wait to try it in my Miata.

Soooo, did you come here for approval for your idea or a solution to your current issues? Adding an infinitely adjustable ECU to your car without resolving the issue(s) is a bad idea. To your argument,"Standalone is as simple as plumbing a few things and plugging in and going. Spend a couple weekends tuning and maybe a dyno session and I'm good to go. Worst comes to worst I plug the original ECU back in and try again." reveals your naivete. What do we know, though? You're a grown-ass man, make your own decisions.

Just a note, quality, good condition, used OEM NA Miata ECUs are not difficult or expensive to aquire.

Also, there are some 20+ year old electronics that you can't really get a new replacement for at a reasonable cost. The '96-'97 exhaust gas pressure sensor is one of them. And there two solutions to one that goes bad. Find a good used replacement or eliminate the EGR system and run an aftermarket ECU. Otherwise you will deal with a CEL that won't go away. Which can be troublesome for anyone in a yearly OBDII insection State/County.

Keep in mind, the parts found sitting in a junkyard and those available from many of the Miata specific breakers are quite different regarding condition.

I only mentioned how a '96 ECU can cure the '97 P0300 issue as it worked, and continues to work, for me... anecdotal as it is. I don't know if I got a killer deal or if it's the usual going price, but $40 for a used ECU is a lot less than any MS option. Maybe it would do the same for you, maybe not, but tossing $40 at a used ECU for your misfire problem is a drop in the bucket in comparison to jumping straight to something like a MS option. At worst, you find out your problem isn't the P0300 TSB and resell the used ECU.

Quote:

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Originally Posted by kung fu jesus

Soooo, did you come here for approval for your idea or a solution to your current issues? Adding an infinitely adjustable ECU to your car without resolving the issue(s) is a bad idea. To your argument,"Standalone is as simple as plumbing a few things and plugging in and going. Spend a couple weekends tuning and maybe a dyno session and I'm good to go. Worst comes to worst I plug the original ECU back in and try again." reveals your naivete. What do we know, though? You're a grown-ass man, make your own decisions.

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Then what would you suggest I do about my current issue? Currently as I see it, the issue is not in how the car runs but the diagnostic electronics.

Did you read any of the posts above? Have you gone through the diagnosis procedures in the FSM? Jamie is serving you a detailed answer on a platter.

I'll try to find one for cheap but when I did a quick search I could only find them for around $200, and that's $200 i'd rather spend into going Megasquirt than another stock ECU. There's also the chance that the ECU won't fix it, and at that point I have 0 idea what it could be as i've checked everything except for replacing the fuel filter but that will go in this weekend. If the fuel filter fixes it... I will be absolutely dumbfounded but I guess the logic of a clogged filter making the engine run lean and mis-firing is sound.

I appreciate the advice and I'm sorry if I come across as naive and obstinate but i'm extremely frustrated with this. All signs point to the ECU but a ton of forum threads all have different solutions for the same problem I am having. One guy said an FPR fixed it for him, another said a new harness and a 3rd said one of the Crank Position Sensor screws was just loose. I agree that $40 is no problem and if I can find one for around $100 I will gladly drop it in and see what happens.

But I have a friend who will sell me a brand-new 96-97 MS3PNPpro, AEM Analog UEGO WBo2 and a GM IAT for $1000. For the time being I was just going to keep it under 6500RPM and work overtime until I can afford to go MS.

Better help than you are offered here you have to search long for.