Mobius

iTrader: (2)

So some of the collective wisdom has been imparted to you in rather harsh fashion. But I would listen to what's been said.

a) unfuck what has been done. The previous owner has, to be gentle, not followed best practices. I would not trust anything that has been done to it. Undo it, and get the car to idle / run on the stock ecu.

b) Megasquirt. Listen to the people who have actually installed ECMlink and have it running on live miatas, and are still recommending to you that you run Megasquirt. MS is the way and the light. There will be some learning curve on your part, which you understandably want to avoid, but your miata community support will be OMG SO MUCH LARGER with megasquirt.

You have turbo and ecu experience on different platforms, which will serve you well in general, but our advice is to start from zero with this car, because we don't think the PO made wise decisions. Take it back to running on the stock ecu, then do things properly.

Leon R

Does Miata CAS incorporate a crank sensor, or is it just a cam sensor?

I have done just this in my Summit. I repined the entire harness to run DSM Link. This is remarkably simple, once you break everything down in a spreadsheet. The ONLY original sensor that I reused was TPS and that ended up biting me in the *** because despite looking identical, it had reversed pin order. But that was an easy problem to solve.


How similar is the MPI circuit? Did you have to wire in DSM MPI relay or did you make the original relay work?


Looks like gauges are, in fact, Ebay crap. Never cared for gauges, anyway. I usually log everything I care about (other than RPM, boost and engine temp).

matthewdesigns

iTrader: (8)

Man that looks really good. Yours? I'm engine out right now for a rebuild and am tempted to go down the tuck and cut rabbit hole. I really just want to drive the car again though lol.

Girz0r

iTrader: (1)

Previous owner:


Shell & interior look decent. I'd find a junkyard 1.8, 6spd & diff and remove the fookery from the PO. And rust repair allthethings. Eventually turbo

matthewdesigns

iTrader: (8)

If you can pull it off then go for it, especially with your previous effort. Most of the time when people ask about this they don't even know what a soldering iron looks like, let alone how to use it. However If I ever build another turbo Miata from zero I'll use MS...it's just too easy to start with it and there's tons of support here.

Miata CAS is essentially identical to a 1g CAS in operation, and there is only a cam signal on the B6 1.6. The '96 1.8 I am building had a crank trigger plate/sensor but I'm not incorporating it.

TPS in a 1.6 (maybe BP too?) is an off/on switch, DSM unit needs to be swapped in. I ended up using a 1g throttle body so that I could use both the TPS and the FIAV. Ditched the DSM TB and FIAV for the 1.8 build and just modified the TPS to fit on the native Miata TB, with that FIAV deleted, too...much cleaner install.

I had to swap in the MPI and wire everything related, though I'll admit that this was my first big wiring project and I may have overlooked a shortcut if one was present. I ran over to the Miata fuel pressure relay and used the stock wiring from there back.

I'm speed density so I don't have the huge MAF under the hood, and use the baro input for my flexfuel sensor.

I'm going to swap my fan control over to ECMLink this time around using the fuel pressure solenoid output since I'm rerouting the coolant and have deleted the front waterneck.

Leon R

Thanks for the info, Matthew! Makes perfect sense! Sorry if I missed it, which DSM ECU are you running? 1G or 2G?


You guys are missing one point, being a hard core DSMer, I have more than just “logical” reasons to run DSM Link in a Miata. It is like when people choose to do engine swap, even when it is much more involved. At least I am not talking about doing a complete 4G63 swap .



Perhaps this will help you understand, my other three cars setup up or running DSM Link:

1996 Talon Spyder AWD (originally FWD auto, converted to AWD 5sp)




1993 Eagle Summit AWD - 11.6 second minivan (converted to 4G63 – 2G DSM Link)







1980 Triumph TR7 (4G63 swap – still in progress, but set up to run 1G DSM Link)

Leon R

The current 1.8 seems to have fine compression.

Girz0r

iTrader: (1)

oh yea 94' IS 1.8 Not awake yet.

Regardless, you're handling a 'special snowflake' project. See if it runs good stock.

You can definitely reuse the BEGi exhaust manifold / turbo (if it's good, no play no leaks) / Downpipe.

Remove musical instrument hose, FMU, bad ecu management etc and you may have a salvageable fun project.

EO2K

iTrader: (37)

The pair of gauges in the center console mount appear to be VEI single display gauges. They are not exactly eBay trash, but I and several others have found the senders to be problematic.

Joe Perez

iTrader: (8)

Gotcha. I was looking at that on my phone while doubled-over in gastrointestinal pain earlier, couldn't quite tell what it was.

I'll just re-state what's already been said. If this were my car, I'd go down one of two paths:

1: Rip out every single bit of aftermarket wiring and hardware, repair all the damage to the factory harness, and try to get it running on the stock ECU, or

2: Rip out every single bit of aftermarket wiring and hardware, repair all the damage to the factory harness, and try to get it running on a Megasquirt.


Option 2 is there only because I am extremely experienced with the Megasquirt, and feel comfortable with them.

But the basics remain the same. Every single wire on that car which wasn't there when it left the factor would come out first, and the damage left behind repaired, before I ever even thought about turning the key.

18psi

iTrader: (76)

Let me make one last observation:
Being a "HARDCORE *insert other car make here* 'ER" is going to hurt you more than help you. Here's why: you're set in your ways.. You can tell us you're humble, and open minded, but in reality this is almost never the case.

The last handful of guys just like you, most of them never delivered. I can find the threads, I can quote their posts, they all talked a big game, they all had hopes and dreams, and all of them were dead set on doing things their own way. Here's the kicker: ALL OF THEM posted the "cool cars" they built in the past trying to impress us.

Want the spoiler alert? most of them amounted to nothing, and quietly stopped posting and then we saw their For Sale threads.

I really hope you don't turn out this way, but it's not promising at this point.

In fact, this is such a common occurrence at this point, that I'm going to save this post just so I can repost it for the next guy, just like you, that will have the same thread, with the same cars, and the same "hardcore *insert other make her* 'er". It will be so similar, I won't even have to change the post.

Good luck

Leon R

I think that you stating the obvious here... I went as far as saying that I am NOT being objective!


I will attempt to get the car running off boost on factory ECU (only) to make sure that everything is OK. Then, I will address the boosted engine management.

aidandj

iTrader: (5)

Yes mathew that's mine. Only part on the car that looks nice

OP, you seem a bit more reasonable than you originally came off.

Running it on ECUlink would suck if the engine won't run on stock ecu. Get it running on the stock ecu then its just a matter of a spreadsheet just like you said.

I don't know about the 1.8 (I'll check in a bit) but the 1.6 megasquirt actually uses the 4G63 ignition trigger algorithm

Braineack

iTrader: (62)

Welcome, Leon R. Check out the Miata Gallery and post up some pics!

Joe Perez

iTrader: (8)

All '90-'97 Miata Megasquirts use the 4G63.

Until the MS2 came out, we also used to retrofit the 4G63-style pickup onto the newer engines as well.

That said, unless the OP is already intimately familiar with both Megasquirt and the use of a dual-channel oscilloscope, I would not recommend attempting to install MS on a non-running car with a butchered wiring harness. Start with OEM, and move from there.

18psi

iTrader: (76)

sounds like a good plan

matthewdesigns

iTrader: (8)

1g, but technically a GVR4 with matching engine harness.

Good job on the other builds, no small feat there on the AWD Spyder. We did a couple at the shop and said **** it, there's an easier way to make a living lol.

hornetball

iTrader: (4)

11 second minivan. Hahahaha. I like you OP! (Take that however you wish, this is a Miata forum).

Takes guts to work on a Triumph too. Haven't seen one of those wedges in forever.

What Joe said. It's the way forward. Clean Miata IMHO. Especially for MA.

18psi

iTrader: (76)

actually I really like that van too lol

Leafy

iTrader: (1)

I think I may have actually met this person. Come to the next devens event and I'll tell you the DSM link idea is bad to your face. 4G63 swap might actually be less work, just a wide block + early B2600 R-series tranny + some welding + factory dsm engine wiring.