Sorry, I should have stepped in here earlier. You’re in the right path, but a couple things: I don’t use the bulkhead usb thingy, I just stick it through the case, gives you a couple extra inches if you want it. And yeah, grab a 3/16” (?) brass vacuum splice from McMasterCarr, put it ~6” from the case to connect/disconnect. Like I mentioned earlier,
you can use an external map, but ive only done it once, and it is $$. And with the expansion harness, I use a DTM 8pin, again ~6” from the case, for ease of removal/install. Goal is to never having to remove the side plate down by the pedals.

 

AH the joys of having your own place to tinker with your own car.
Gives you excuses to buy more tools.

Also, congrats on getting a "real" ECU, the link will definitely be a step up in terms of capability.


And it's eerily similar what state we're both in at the moment. I just stripped the Piggyback Harness from my MSM and it's all over the office floor getting reconfigured.

 

Also, I have a tune for you to try, you shouldn't be struggling to idle, so either try it and see if it works, or just compare the settings, you probably have a table zero'd out, or are just on open loop idle. Haven't looked at a base map in a while.

I'll PM you for your email, because apparently I can't attach Link tunes here.

 

If you want or need to make the expansion, USB or CAN cables yourself, the connectors at the board side are JST XA. You need a special crimper for those. I haven’t done it myself, but did find a post where someone recommended this.


The post I’m referencing https://forums.linkecu.com/topic/102...-part-numbers/

 

Thanks guys, lots of good input. I realized even if I get the car to idle, I won't be able to drive the car without a laptop in my lap, so I've got a USB extension on it's way.

I will consider adding another connector for the expansion cable as well. It would be a good project to work on my wiring skills.

 

And we're back. Got the tune from Curly, cross referenced some of the settings with the map I was using and got it fired up and idling without much fuss.

I changed quite a bit at once, but among the changes I made I think the most important were changing the trigger from falling to rising edge and adding a good amount of fuel at idle. I noticed in the logs that the RPM was dropping to 0 as the RPM's were coming down after startup and it looked like it was losing the trigger signal, so I'm guessing that edge was incorrect. My AFR calibration was incorrect as well, but I got that sorted with a linear calibration table. 0V = 10 AFR and 5 V = 19.3 AFR for anyone who's curious.

Base timing was set, resulting in -18 degree trigger offset. A bit of a difference from the 210 I was using at first.

Enabled ignition based idle correction, fudged some numbers into the VE table and took it for a drive.

Wow, first impressions are really promising. I drove around town, got on the freeway and went to home depot (pretty much a daily routine at this point). Hot restarts are still really lean, but the car idled pretty well for base settings. The car idled fine driving around town, felt stable, no major dips, no stalls. It definitely returns to idle a lot better as well. If I clutch in at 3K and the revs drop the car doesn't shudder at all and the revs drop smoothly.

I don't want to overhype it, but I'm pretty excited to dig in. I haven't pushed it at all, but for putting around town I'd say this is pretty close to my old tune/setup that I spent a good amount of time dialing in, and arguably better in some ways.

I also noticed that my fuel table values are surprisingly similar to the numbers in my Speeduino map. For example, in the Speeduino map I was idling around 66 and tonight on the Link I was running about 60. So for now I'm going to sit here with my Guinness and copy over the values from my old map to the new one. Obviously I'll be doing a lot more tuning of the fuel table, but I think the old values should be in the ballpark of what I'm looking for.

Overall, pretty stoked. Based on cruising around tonight I'm already pretty confident in the car. Lots of fine tuning left, but feeling good.

Also, that stupid clunk in the rear is starting to **** me off. Next on the list is getting under there and disconnecting the rear sway bar to see if it goes away. For context, here's what it sounds like. This was all over the course of about 5 minutes of driving. I think it's the rear sway, but if anyone recognizes this as something else please let me know. It's most prevalent when taking off in 1st gear, but if I shock the drivetrain, for example stabbing the throttle in 2nd, I can replicate it pretty easily.

 

have you checked your driveshaft universals recently? sounds like a tick there to me. hollow ting. when load is applied.
maybe you ate a few needles.

 

I did get under the car and looked around a while back trying to identify the source. I remember grabbing the shaft and checking for play but didn't notice anything that seemed strange to me. I'm not super experienced though, so there's a decent chance I missed something. I did replace my driveshaft with this unit from a junkyard a couple years back. I got some definite driveshaft noise right before a big roadtrip so I just threw in the quickest option. I think this one had 100K+ miles on it.

Good lead there. I'll look into that and see if I can find other examples that sound similar. I've had some tunnel vision on the sway bar idea since this started around the time I installed new suspension and the rear bar.

 

CV axles can do things like that.

 

Alright, well I've got a few new things to look at. Found a couple thread on Miata.net that mention a very similar sound, but no resolution on those threads. Driveshaft and CV seem to be the most likely culprits.

I should've posted that video a while back. It's been like this for a while, including a weekend of autocross.

 

Just to confirm, it’s only under driveline load? Doesn’t clunk under cornering or general suspension compression?

 

If you trust a buddy, what you could do is put the car on stands, pull the parking brake up a couple notches so the brake drags, and have a buddy do some pretend takeoff from stop while you're underneath looking for the sound.
Just don't grab the spinny things, and friend needs to know not to rock the car hard. you might have to test an ever increasing load with the parking brake to get it to happen consistently.

This will narrow down whether it's drivetrain, or suspension.

 

@Z_WAAAAAZ Correct, I've only ever heard it under load. Never in reverse. Mostly when releasing the clutch and starting to move.

Thinking about it now, the swaybar doesn't seem like a likely culprit. I originally thought it was the end links binding when the car squatted, but it happens when putting around parking lots as well, and I'm not exactly launching the car there.

@Ironhydroxide I'll keep that in mind. I think the first thing will be to get the car up and check the axles and driveshaft for excessive play.

Also, assuming that's the culprit I'll be taking driveshaft and axle recommendations. I'm not looking for anything more than OEM style replacements, but if there are brands to avoid let me know. Z, I assume you're the expert here.

 

Glad to hear it's all going better now! Interesting about your offset. I was hoping I was the oddball with a -22, but yours is close. I wonder why such a difference from those curly and others on the Link forum have used, but if it works then so be it I guess.

 

I wonder if it's variances in manufacturers? I'm not sure if FM, 949, Fab9, etc... all use the exact same location for the cutout or not. If they varied by a couple teeth than the roughly -10 degrees that Curly's seen and the roughly -20 that we're seeing would line up pretty well.

FWIW I'm on a FM wheel.

 

Ding ding ding, we have a winner. Last weekend I got under the car and poked around a bit more thoroughly. With the car in gear I spun the rear wheels by hand which cause a decent amount of shock load to run through the axles and driveshaft. I felt just a tiny tiny bit of play in the joint when spinning/locking it. Heard a very quiet version of the pinging that's been plaguing the car. Ordered a Dorman unit (PN 936-251) from Amazon which arrived today. Suddenly, no pinging/clunking. I can finally drive my car through parking lots without sounding like I'm beating a hollow pipe with a hammer.

Install was pretty standard. A bit tight with the 3" exhaust but the driveshaft shimmied in without too much hassle. Got to use my 3d printed trans plug. The car was nose down but I'd rather be safe than covered in trans fluid.


Outside of that, I spent some time this weekend doing more ECU related projects. I got a 6.5 ft USB extension installed. Wrapped the junction between the two cables in Tessa tape to help prevent it from separating and then routed the whole thing behind the HVAC and into the glovebox. Plenty of cable to set the laptop on the roof above the passenger seat. Side note, my HVAC won't let me go to the cold ranges right now. Not sure why, but I tried to move to cold air and it's like hitting a wall. The switch simply won't go. Not a problem right now obviously, but something that'll have to be fixed at some point.

I had previously removed the power steering idle up signal wire from the pump and wrapped it up with some other wiring. The SpeedyEFI boards didn't have it wired in but when I was poking around in PCLink I noticed that it was setup and enabled. It makes a surprising difference. I think I just got used to it being disabled and the RPM dip wasn't dramatic without it, but it's just another small thing that makes the car feel way more refined.

I'm really impressed with how drivable the car is with minimal tuning. I wouldn't hesitate to leave the house right now without my laptop and cruise around town. I'm still mostly on open loop everywhere, so I imagine it'll only get better. VE tuning is a bit harder right now as it's only getting up to about 5-10 C (~40-50 F) in the days and I'm mostly cruising around at night when it's even cooler. The car will get to thermostat temp quickly enough, but it takes a while to get a good amount of heat into everything to get more consistent numbers. Hopefully now that the driveshaft is fixed I'll get the car out one of these evenings for an hour or so, dial in the fuel table and then start testing out some closed loop idle/fuel/boost controls. I'm still learning how PCLink does their auto fuel tuning as well, but think I figured out some filtering settings that should make that work better as well.

 

I got the car out and did some tuning on Saturday. Mostly trying to dial in the fuel map and start to play with boost control. My fuel map wasn't as 1:1 with my old tune as I originally thought, but it's getting there now.

Another cool thing about the Link is that every plug in the engine bay is available for I/O (with some limitations). I wasn't able to run EBC from the purge solenoid valve. That's how I've had it running in the past, but now that I can actually run an EVAP solenoid I was going to move EBC somewhere else anyway. Rather than run new wiring from the ECU though, I was able to tap into an unused o2 heater circuit and use that for EBC. Then I realized I could swap my wideband and EBC and clean up a good deal of wiring. A little bit of time connecting up some pigtails and we've got plug n play boost control and wideband o2.



A while back I got a really good deal on a used (slightly questionable) Flow Force LS coil kit. The more I think about it though, COPs seem more attractive to me. Less bulk, less weight and are going to provide plenty of spark.

I was poking around on Ballenger and I'm pretty sure they have the pigtails that connect directly to the 4 pin connectors on the NB1. I'm not sure if these are new, but I was under the impression they didn't exist. So that got me thinking, why not just adapt a harness from a 4 cylinder that already runs the R8 style coil packs?

Clipped straight from a GTI ('06 I think?). $45 for the harness and coils


If I hadn't grabbed the actual coils, I think they were only going to charge me $5 for this wiring.

Things to note.
I didn't realize/ask how much the coils were going to cost. These were pretty exposed to the elements and were about $10 each. New ones from Rock Auto are about $20 each, so probably not worth the gamble.
I broke about every clip trying to get the coils unplugged from the harness. They still seem to hold pretty tight regardless. Depending on how this project ends, I also might go back and make a v2 at some point.
There are a surprising number of cracks in the wiring insulation, both on the power and ground wires, so I will be wrapping those up separately most likely.

So, we've now got a harness that's wired for full sequential ignition. I would love to find existing signals (maybe from the EGR plug?) to get the coil 3/4 signal wired up, but might just use the expansion harness and run it through the firewall. The power and ground wires will need to be split to accommodate the 2 coil pack plugs on the Miata's harness.

I've also been thinking about this for a while and have been trying to figure out a solution for sealing these in the spark plug holes. I got these home, threw one in the hole for cylinder 1 as a test fit and it definitely does not seal. However, it was pretty close and I had some grommets laying around. I trimmed one lip of the grommet down and well, would you look at that.



3/4 Inch Grommet from Home Depot

I was at Home Depot yesterday and realized that if you buy these individually they're like $3 a grommet. This was mostly a POC, so I'm probably going to see if I can find something that fits even better on Amazon. The fitment really is impressive though. Grips the stalk of the coil really tightly and sits perfectly into the spark plug hole.

I need to go pull the coil pack connectors to make sure I get the right pigtails from Ballenger, but I think it's going to be another hour or so of work to get these up and running. All in, and assuming the coils aren't fried, I think the total cost is likely going to be about $70, and $20 of that is going to be the pigtails. If you went with brand new coils I'm pretty sure you could still do this for right around $110.

Once I've actually tested this I'll probably do a standalone writeup. Seems like a pretty easy and cost effective way to DIY some COPs.

 

Dude nice work on finding all of that for cheeeeeeeeap. I wen't the easy button and bought the set from GFBDevelopments for mine but damn, it's impossible to argue with your find. I posted the dwell times in my thread in case you don't have those yet, and you can always make it a 3D table with MAP in one axis if you run into spark issues at lower dwells (but I highly doubt it). I can't check at work, but I think the Ign3/4 pins are only available on the expansion connector in the NB1 and NB2 ECUs. If you do open up that case again, I would put a CAN and both expansions while you're at it. I personally don't enjoy repackaging that box.

I'm going to ****** one of those grommets for mine asap.

I hear you talking about EVAP solenoid. If you're planning to keep using Aux 12 for it, grab that sine function I made for PWMing the output and give it a whirl. I found on/off made the car too rich, but it may be better with a plenum. You can always use the 4D/5D fuel tables to adjust the mixture when purge is active too. The Link has a purge function but it uses MAP instead of MGP for its activation. That means if you ever hit elevation it may be active all the time. I don't remember the baro where you live, but I believe it activates under 90kPa, and the highest baro I see around here is 86, lowest is 68-71. But you can use a GP Output to make your own logic. Happy to help with any of that if you go down that route.

 

Good point on the outputs. I'll need to do more research to see if the Aux channels can drive a coil signal. I assumed they could since the power is coming from another circuit, but I might be giving the ECU too much credit. Probably just a little more excited about this find than I should be.

Regardless, my EGR is deleted already and I noticed 4 aux signals are piped to that plug. I think I found the mating connector on Ballenger for $9. If so, that's a pretty useful "expansion harness" by itself.



I will likely reach out about the evap stuff at some point. Mine was mostly deleted when I got the car, but I was thinking I might just throw a cheap solenoid in there with a fuel filter on the line and see how that goes. When I tried going the VTA route I just ended up with fuel in my fender wells. I could fill my tank, but was probably close to burning the car to the ground as well

 

I'm almost certain you can only drive ignition signals from the ignition outputs, but there are 8 of those so you have plenty (6 without the expansion). Ignition outputs have internal modifications to prevent backfeeds, and the AUXs don't have this (It could be the other way around. The docs have a matrix of what can be used for what, but I can't access it right now). If you don't want to use the expansion ports, the latest firmwares allows you to re-assign cylinders to any ignition outputs at will, (i.e assigning ign 6 to cylinder 3, etc.) so you could move the pins around to make that work (fuel pump is an ignition output from memory). But ign 3 and 4 are on the expansion port.