Make a German Car Whore love a Miata! Flyin M Miata thread!

The Link lives in the stock ECU case, so it's behind the passenger's seat. You don't need physical access to it, though, you just need the ribbon cable that's attached to the keypad. The SerialLink plugs in to that. You do have a keypad, right?

The ECU will tune to whatever targets are entered, and only when autotune is turned on. If you tell it the wrong AFRs and/or turn it off, it won't magically fix problems. A wideband will give both you and the ECU better data to work with, narrowbands are really only good at identifying stoich.

Fuel is based on a MAP vs RPM table with some modifiers laid over top. Rows 100-300 are vacuum, 400-600 are boost.

In reply to Keith Tanner :

I do have the keypad.  Happy to hear access is so easy!  So I unplug the keypad and plug that into the Serial Link and that gets plugged into my laptop? 

Hmm, so if it'll tune to whatever is entered, how do you know you're setting it where it needs to be without a wideband O2 reading?  It looks like you guys tuned it back in the day but then a local shop has played with it some since.  I don't know how much they've played with it.  It looks like they did it when the previous owner brought it to them to get it thru somg.

When I datalog it will it give me O2 values?  Like at idle it's seeing 12 vs stoich, or on boost 10 etc?

So a little update, I took advantage of Harbor Freight being 5 minutes from my house and bought an LED work light that attaches to the hood.  Now I can more easily work on the car at night when the kids have gone to bed.  Woot!  I also happened to be on the phone with anthonygs, who's sending me a set of wheels/tires for the car, so I've got that taken care of.

I talked with the shop that's gotten this thing thru smog the last few years as well as Flyin Miata about tuning the Link.  It seems like what the shop did was hook it up to their exhaust gas analyzer and pull master fuel until it was below smog thresholds, then take it thru.  I know the previous owner pulled "4" out of master fuel last time and failed smog.

Since I don't have an exhaust gas analyzer and the car almost passed with "4" taken out I think I'll take out "6" from master fuel, bring the thing in smoking hot and see if it passes.  Depending on what the smog results are, I can adjust up/down and then bring it right back and have them retest it if it doesn't pass the first time. 

If that doesn't work I'll find a shop near me with an exhaust gas analyzer and bring the car and and play with the fueling and watch the results, then find a "smog tune" but I suspect I can figure it out myself.

What I really need to do is add a wide band O2 gauge/sensor to the Link.  Not only will I be able to see WTF this thing is doing AFR wise but then I'll be able to tune the Link while under boost.  Right now, with the factory narrow band O2, the Link can only be tuned under vacuum...

That's how you hook up the SerialLink, yes. One of the failures experienced by aging Links is broken solder joints on that ribbon cable connector inside the keypad caused by flexing as you connect/disconnect it over time, but that's easy enough to fix by reflowing the joints. Symptoms are garbage characters on the keypad. 

Narrowbands will give you SOME info on AFR outside of stoich, but it's not terribly accurate. If you're aiming for stoich, they're a good option and very quick to respond.

If you datalog, it will give you both the map (which you can save) as well as instantaneous readings on basically everything the ECU is reading or generating. It can be graphed using DataLogLab.

https://flyinmiata.com/FMcontent/dataloglab/

Simply going lean isn't always the best choice.

In reply to Keith Tanner :

Understood.  But since the previous owner took out 4 from Master Fuel and it failed CO but easily passed HC and NOx, it was still too rich.  So I'll take out 6 and see what it does.  If it fails NOx and easily passes HC and CO I know I've gone too lean, or if I still fail CO and NOx is still really low I know I have to take more fuel out. 

I'd get a datalog of the car under emissions test conditions. Since you're aiming for stoich, you can get good info out of that narrowband. If the targets are right and you're running closed loop, you'll see it dither back and forth across the threshold.

Probably quicker and easier than trial and error at the emissions shop.

Very cool little Miata you picked up. If you want to try out some low-pressure autocrossing check out Pike's Peak International Raceway's Time Attack series. It's for fun and not a bunch of rules. There are quite a few other turbo Miatas that compete, including mine. Come out and check it out for a day! https://ppir.com/2018-time-attack-series/

Finally started working on this last night.  Note:  I'm loving my CPAP!  I now sleep well enough at night that I don't pass out early in the evening and had plenty of energy to work on the car after the kids went to bed.  Result!

First, hooked up my new Harbor Freight light, really nice!

Next I removed the air filter, sprayed it down and washed it out in the kitchen sink.  I really wish I had a laundry sink or a sink in the garage.  Oh well.  I checked it this am, thinking I'd have to do it again this afternoon with the hose since the sink didn't have a lot of water pressure and I was pleasantly surprised at how clean it looks.

Then I replaced the coolant temp sensor, since I want the gauge in the cluster to work.  It was $16 from my local O'Reillys.  Kinda of a pain to get to, you have to remove the coil pack from the back of the head and it's a tough fit to get your 19mm wrench on the sender itself.  Luckily it broke free without too much of a struggle and I R&R'd it.  I found it easier if I removed the bolt holding the hard line onto the firewall.  That gave me plenty of space to move the coil pack out of the way.  Sorry, no pics, didn't think of it until it was too late.

I tried to drain the fuel out of the tank but OMG is that bolt on the bottom of the tank on there tight!  So I'll use the fuel pump method instead, I just need to get some fuel line.  Anyone know what size I need?

I also bought an exhaust tape kit and put that on.  I'm not very optimistic about it tho, the stuff didn't seem very sticky.  I have a feeling when I check it later today I'll be peeling it right off.

Today after work I want to do the oil change and pump out all the old fuel.  Then hopefully tomorrow I can take 5 or 6 out of Master Fuel on the Link and take it thru smog testing...

I love the light.  It’s going to be friday after work to send the wheels and tires.  Yesterday after work got busy and tonight I’m taking the m96/97 online build class for my p car engines.

I have that same light, and I had no idea it had little bungies in the ends until just now!    Thanks!

In reply to Rodan :

Your welcome!

So I had to get the miata off the lift tonight.  I brought the 911 back from the shop, where it got boost leak checked and fixed but it threw misfire codes at max boost.  So I need it on the lift to finally get the spark plugs/coil packs done. 

Normally not a problem but it's supposed to snow tomorrow, so that means neither of these cars will be able to move tomorrow.  Not only that but that totally rains on my parade with the miata as I was hoping to take it through smog testing tomorrow.  Oh well, guess I'll wake up and see what the weather's like and just get ready.

So I did an oil change.  OMG is that oil filter the biggest PITA to get to!  WTF were the Mazda guys thinking when they buried that dinky little thing underneath the intake manifold?!  My hands are way to big to get at it from above, so below is the only way.  Then whoever put the last one on must've gorilla'd it on cause it was moving for nothing.  All my strap oil filter wrenches were too big because Ze Germans, zay use much bigger oil filters, ya?

Luckily I had a Griots Garage oil filter huge pincer wrench remover thingy.  That worked.  Not easily tho.  Finally got it off and put the new one on hand tight.  Hopefully it plays nicer with me when its time for take it off.  Lift FTW btw!

The exhaust tape job actually doesn't look all that bad...  It did help with the exhaust leak but I can still hear it.  So a new exhaust definitely needs to happen.

Then it was oil the air filter, pop it back on and off the lift.  I decided to drive it around a bit and see if replacing the coolant temp sensor brought the gauge back to life plus I wanted to get some fresh 91 to put in after I pump out the old stuff tomorrow am. 

Happy to say that yes, the sensor fixed it but man, that gauge barely came up.  It basically sat on the "C".  It was maybe 40 out but still.  I did hear the cooling fans come on low speed, so they work.  Pop up headlights work.  Headrest speakers work but the headunit is trash.

Got gas and put it away.  I'll jumper the fuel pump tomorrow am and pump out the old fuel, have 3/8's of a tank.  Put in the fresh 91 and wait for the weather to clear to take it through smog.  Can't this weekend, working at the base.  Can't next weekend, taking my son skiing.  So if not tomorrow, then 2 weeks...

Oh added the Miata to my Hagerty policy.  $10,000 worth of stated value coverage for a whopping $21 a year!  Woohoo! 

Well woke up to snow on the ground today.  Drat!  Also my daughter still has the stomach flu, so gotta take her to the Doc.

Took my son to the bus stop, took my daughter to the Doc.  Not really enough time to do spark plugs and coil packs on the 911 before my son comes home from school.

Well, lets work on the miata some more.  The fuel in it is easily 2+ years old.  Lets get that outta there.  Initially I was going to pull the drain plug on the tank but it was on there incredibly tight and the last thing I want to do is strip the tank taking out the drain bolt.

So, lets use the fuel pump to drain the tank instead.  You need to attach some fuel line to the appropriate line.  This one, here

Note the fuel line directly to the left is NOT the feed line, it's the return line!  Don't be dumb like me and try and attach to it first, you'll just pump fuel all over the engine bay and garage floor.  Luckily I caught it really fast.

Put the other end into a gas can.  I use this one for racing, holds a bit over 5 gallons.  Gauge read 3/8's of a tank, this can should be big enough.  I hope!

Then open the diagnostic port and jump the fuel pump pin with the ground pin using a paper clip.  Handily Mazda marks which pin is which on the back side of the port cover.

Turn the key to ignition on and wait till the tank is drained.  I had 5 gallons left, I basically filled my gas can.  Plan is to dump it into my wifes rental car tonight when she gets home because I could care less about the rental.  Shhh....

One of the local Miata Turbo guys chimed in on my thread on miata.net about getting this thing past smog and told me to take "6" away from Master Fuel and I should be fine.  Drive to the smog place, stop a block away, take away 6, put it thru the test.  Drive a block away, put it back in.

That's the plan, hopefully the weather is nice in 2 weeks and I'll try to get it past smog.

The amount to take out of master fuel all depends on the rest of the tuning. Taking out 6 will be leaner than taking out 4.

Fun trick - you can also honk the horn through the diagnostic box. I don't know why.

In reply to Keith Tanner :

Yup.  Since it failed CO last time and the previous owner took out 4, I need to take out more.  So I'll try 6 and see what happens.  Limit for CO is 15 and it blew 20, so still a ways to go.  Once I get this thru smog I'll add the wide band O2 and tune it with that to get it closer to where it needs to be.

So the guys on miata.net pointed out to me that the the coolant temp gauge in the cluster uses its own sender and it's NOT the one I replaced.  Doh!  It's even harder to get to but apparently it rarely goes bad, so I was told to make sure it's hooked up.

After moving the coil I could see the sender and the wire was attached but not all the way on.  So I took a long screwdriver and shoved it all the way into place.  Still cold with snow blocking the end of my driveway, so I didn't start the car up and see if that did it.

My "new" wheels/tires arrive Wednesday night, so if the weather cooperates I'll back the car out into the driveway to put them on and then let it idle to see if the coolant temp gauge registers properly now.

I was also advised to remove the 180* thermostat the previous owner had put in and go back to stock.  Should I?  My thoughts are it just opens up a little sooner than stock but shouldn't make any difference.

Keith Tanner said:

The ECU and the gauge use separate sensors. You can check to see what the ECU thinks the temp is via the Link keypad.

I’d put in a correct thermostat. If the car’s running too cool, the ECU won’t go into closed loop.  

In reply to Keith Tanner :

Yeah, I read that but didn't sink in.  I thought the sender I replaced was the one for the gauge.  Oops.  My german cars use one sender for everything, for better or worse. 

My thoughts on the t-stat as well.  If the car runs too cold, it'll run rich, which will make it awfully hard to pass emissions and make me chase my tail with the tune to try and get it to pass emissions.  I'll pick one up today from the parts store and put it in tonight along with new spark plugs.  Then, hopefully I'll be ready to take this thing through smog testing and see what happens.

Fun fact: the NBs use a single sensor - but if you look at the wiring, it's actually two separate senders that share a single housing. I don't know why Mazda separates them. On the 1.6, there was an ECU sender, a gauge sender and a thermoswitch that runs the primary cooling fan.

And for future readers who want to know which sender is which, the gauge uses a single wire and the ECU uses two wires.

Thanks to Anthony, I have a set of Kosei wheels with brand new tires sitting in my garage right now!  Lug nuts should arrive shortly.  Plan is to put them on this Sunday, then drive around with my laptop hooked up to the Link so I can play around with fuelling.

Tonight I'm going to put new spark plugs in, that the previous owner gave me, plus a stock thermostat.  After that, it should be good to take to smog...

Ok, got the tstat and spark plugs done last night.  I was a little worried about my spark plug socket, the little inner rubber bootie was coming off on the plug end.  I reseated it between plugs and it turned out ok, but I should probably replace it...

Taped it to my extension just in case, didn't want to lose it in the head...

Plug #4

Plug threads were a little oily, may have to pull off the valve cover so I can replace that gasket there.  electrodes look good but seems like its running rich.

Next up was the t stat.  No pics of that as I was trying to minimize coolant spillage.  I was rather unsuccessful with that unfortunately.  The t stat being mounted horizontally didn't help.  Anyways, got the old one out and new, OEM like one in.

Next up is putting my "new" Koseis on the car this Sunday and driving around with the data logger plugged into the Link while playing with the Master Fuel.  I'd hoped my newer laptop would have the proper serial port but it doesn't.  Hopefully my older garage laptop does...

Ordered a valve cover gasket from my local FLAPS.  I'm leaving at 3 to go skiing, so I'll pick it up Saturday night and put it in then.

Turns out what I thought was the cable for the Serial Link so I could data log isn't.  It's some unidentifiable serial cable for who knows what.

Long shot Keith, but are those cables still available?

There's no special serial cable, it's just a standard 9 pin unit. If your laptop doesn't have a serial connection, you can get a USB-serial converter.

In reply to docwyte :

Remember that you need little dabs of RTV with the valve cover gasket so it will actually seal at the corners. 

In reply to Keith Tanner :

Hmm, ok, that is the correct cable then.  So I;m confused, how do I connect into the ribbon cable that plugs into the Link display?  Or is there a serial port on it? If so, is the serial port on it male or female?

The cable is a 2 row pin out, my laptop has a 3 row serial port.  I'll order the USB -> serial port adapter on Amazon tonight

Seth, yup, have the silicone ready to go...