grippgoat

iTrader: (1)

This will probably do the trick for the VICS.

http://www.diyautotune.com/catalog/p...ans-p-126.html

-Mike

AbeFM

iTrader: (3)

They just use a 222a, er, I have a lot of those. Huge econo-pack.

But, can they handle the current of runing something like a fan solenoid or two? I have no idea what the draw on those is!!
-Abe.
<edit>Answer: Totally. The assortment pack I got from radioshack (what's the difference between them I don't know) says 800 mA on the back - both fan relays together draw 260 mA. So I'm in the clear on fams

P.S. Can't I use the LED15 output, too? Whichever that middle LED is. I'd love to drive my fans with it, if I could. I just have one wire going to both solenoids.

<edit> I still want to know now on this. I guess I could take out the LED... Then I'd know the current. But I kinda wanted the LED as a fan-on-indicator.

AbeFM

iTrader: (3)

Wow! The 2N3904BU's that run the lights on the front of the MS are only rated at 200 mA! That's really low. And the data sheet says 100mA is their max "useful" switching current.

I have piles of these 2N2222A's are rated at 800 mA. Why radioshack packaed transistos good to 100mA in with ones good to 800 and didn't label them as such bugs me.

Anyway, I'm pulling my three LED transistors out. I guess there's a chance these 2222A's are slower, but... No, even the rise and fall times look similar. That's it, out with the old, in with the new. :-)

Joe Perez

iTrader: (8)

Abe, looking good. Yes, two days into my vacation and I'm breaking the internet embargo.
I can't speak to the NB, but on the 1.6 the IGN lines are active high. The The coils begin to charge on the rising edge, and then fire on the falling edge.

Yellow trace is trigger voltage, blue trace is coil primary current.

Edit: That's odd, there was supposed to be an embedded image here. Oh well, here it is as an attachment. I took this one both to figure out polarity and to double-check the dwell times that everyone is using. I found that the EMU was giving me about 5.5 msec dwell at idle, but under 4msec at all positions off idle (this trace is at 2,000 RPM) As you can clearly see, the coil is not fully saturating here, so WTF!? Just another reason to go MS over EMU.

AbeFM

iTrader: (3)

Glad its relaxed enough you have time to break it - just don't waste all day online. Everytime I go home, I'm so swamped I couldn't get to a computer if I wanted, then I need a vacation when I get back.

All excited to try the car out. Here's my complete list of shared pins:

Both B/Y A 3 Chasis GND
Both B/Y B 3 Chasis GND
Both B/L C 3 Chasis GND
Both B/R F 3 Sensor Ground
Both B/Y A 3 Chasis GND
Both B/Y B 3 Chasis GND
Both B/L C 3 Chasis GND

And complete list of ECU only pins
OEM BR/Y L 1 Data Link Connector
OEM G/R H 1 Const. Power (30A Fuel Inj Fuse, feeds Main Relay)
OEM W/B D 2 Instrument Cluster
OEM I/R A 1 Const. Power (80A Main, 20A BTN1 fuse and 10A Room Fuse)
OEM G/W D 1 Data Link Connector
OEM W/L E 1 Instrument Cluster
OEM G F 1 Brake Switch
OEM LG/B L 2 Mass Air Flow Sensor (B, Signal)
OEM GY/R O 1 Generator
OEM GY T 1 Generator
OEM G/O K 2 Data Link Con, Trans Ctrl Mod, Inst. Clust
OEM BR/R Q 1 Insrument Cluser
OEM BR/B K 3 Insrument Cluster
OEM P/L B 2 Air Intake Temperature Sensor Signal
OEM/none? BR/W I 3 Cruise Control Module + Clutch Switch


Basically, the computer only "shares" power and ground, and only sees :
brake switch, alternator, AIT, clutch/cruise switch, brake switch, MAS and the OBD-II port and guage cluster. I imagine I can lose the brake, clutch, and MAS (that's only on there so I can spy with OBD-II readers to see what it looks like) meaning I'll be down to guages and alternator stuff.

Once I put an alternator box from a mopar in, I'll be down to guages. It seems I'll QIUCKLY be rid of the OEM ECU altogether.

But tonight, try to start it. I have a drooping idle, but havent tracked it down. Maybe BOV or intake manifold leak or...?

Joe Perez

iTrader: (8)

Before you go chucking the alternator, figure out how that control line works. The two wires- one is a voltage sense and the other is field coil control (one's an in, one's an out.)

If you can document the relationship between them (and CLT) then it just might be possible to make the MS drive the alternator. Wouldn't that be cool!

AbeFM

iTrader: (3)

Oh, totally cool. Only, I'm running out of ins and outs, and it's not even baking me cookies yet. What the hell?

I was hoping to be able to free up 40 or 50 of the 14 wasted ground pins on the DB-37, where I'm sure 4 or 5 would do - and recycle them. But since I've gotten no information about whether they are connected on an inner plane, I'm just assuming they are, so it's looking like anothe connector is the answer.

Anyway, right now I'm thinking of buying the $12 NAPA regulator which will do it. Otherwise, it may involve something more sophisticated than a silicon relay. I'd like to incorperate it on the board, but if I have to make an analog measurement and have an analog output, I think I'm going to waste functionality I could employ elsewhere.

All down the road. Right now it's making a cable as described above and plugging it in to see what gives, on the stock 265 cc injectors. If they work, in go the 650's. If it'll start and idle there, I might take it out of the garage.
-Abe.

AbeFM

iTrader: (3)

This is really just for notes. Maybe it'll help someone someday.

Joe, you'd mentioned the amount of stuff in the car there to fail you on emissions. Well, I found another wire I didn't know what to do with:
CDCV. It's a solenoid that works in concert with another and with the vacuum sensor in the tank to both keep you from polluting (good) and make things more complicated (bad). I'm just hoping not hooking this stuff up doesn't do something dumb like have me always sucking fresh air in through the charcoal canister. I'll try leaving it off, initially. And maybe later I'll set up a circuit to make it purge that ONCE when my temps cross 130* F or something. Wouldn't be hard to do. I can lose the pressure sensor and the self check, but something to clean out the charcoal as described below (for an MPV) might be a sane thing to do.

cjernigan

iTrader: (13)

Not that i'm into pulluting or that I would do this myself. You can remove all of that crap and replace it with a small filter venting to atmosphere if you don't want to keep it anymore. Pretty sure rmcelwee did that.

AbeFM

iTrader: (3)

Yeah - I was thinking about it - then again, if I ever have to put my car back to stock, that's a big PITA. I thought it might be really easy (just one output) to get that to work. Maybe I could even run it in parallel with my fans - when the fans turn on, it vents the carbon canister. I'm not a fan of check engine lights or hurting performance, but if I can have the same amount of fun and pollute less I'm into it.

AbeFM

iTrader: (3)

Sigh. Well, the car didn't want to start, swapped the coil packs back and forth a few times - it kept losing the trigger pulses while trying to start.
I remember someone's comment about things working much better looking at falling edges on the triggers and that solved that issue. It's doing the thing where you have to crank two or three full revs before it knows where it is, but it starts reliably now.

A couple buddies dropped by and got my idling right quick. I was very impressed. Shortening the dwell time substantially picked me up all kinds of smoothness, and instead of barely staying alive at 1800 it idles rock solid at 7 or 800. Still running on the stock injectors.

Fuel seemed to work fine. I had three issues:
1) My battery charger wasn't working and I didn't know, so running my stereo for two days of soldering left my battery down at 10 volts, and was cooking my buddy's alternator while he tried to keep my car working. Ooops.

2) The "test" part of megatune was screwed up. First it ran the coils (which were acting funny) but the time was way wrong - I couldn't get under 5 ms dwell time no matter what I did! Changed some settings, and it started running the injectors *instead* of running the coils. The weird part is it wouldn't go back to running right even after rebooting MT and the MS.

3) Here's the bad news: I cooked a coil! ****. They are like $600 a set, I'm pretty annoyed about it. Thankfully, I had one coil left over from my original set that went bad, so I've swapped it in. But I really don't want to do this anymore. I didn't flash anything. It got hot, too hot to touch, just from being on. The longer I ran it, the hotter it got. Then I was running on two cylenders.


So, yeah, I'd like a little help on number three! I don't want to keep cooking coils. I'm thinking that I had the "inverted" or active high setting on the coils, and maybe that was wrong? When I was doing the testing (which was buggy so I don't trust it) the pulses were definately down-going. Now I think this was a bad thing. The car was running like that, save for a couple issues. I had to set the trigger offset to 18 degrees to get the spark right on 0, the setting under basic/timing.


Other than that, it idled great, I turned off the idle valve and it was still idling solid. The IAC works (it would hunt like mad when it was still not running right) - but it's LOUD. Turn the car on and you can hear it pulsing away. It can't be good for it. My guess is that the frequency is too high, I'd love to know how to set it right. I have a couple of scopes, but don't know what to look for. So tomorrow, if I can find a new battery, I'm going to try to get it running again - and check into the weird issue where I'm not sure my injectors I bought will fit my car.

Joe Perez

iTrader: (8)

Abe- this reminds me of a problem that some 1.8 users were having- frying their coils after installing an EMU.

I never actually witnessed it myself, but my understanding is that it turned out that while the documentation for the EMU said to set the ignition triggers to 5 volts (which was correct for a 1.6) a couple of 1.8 owners scoped their ignition outputs and determined that they were +12. Setting the EMUs ignition trigger output to +12 apparently solved the coil-eating problem on these cars.

I wonder if on an NB the ignition outputs pullups ought not to be from the +12 line?


Did you look at my attachment above? The coil primaries begin to conduct when the trigger goes high, then discharge when it goes low. I'm pretty sure this is the same for all Miatas.


FWIW, I scoped the IAC valve on a 1.6, and it operates at 160Hz. On the MSI anyway, that's 10000/x = 62.

AbeFM

iTrader: (3)

Huh. Interesting. I assumed it was 5V. I set the settings opposite from the directions, and got to put the timing back where it belongs instead of 17 degrees off. :-) After playing with the scope, the best dwell ended up being 5.0ms, which is exactly what the DIYAT docs say. Maybe they said 4.5, but anyway, it's just where the coil current starts to taper off.


Yeah - I think I read some MS-I stuff, you guys use a different circuit maybe for driving them. My circuit inverts, so what the ECU thinks is active high is really active low. Anyway, it's great right now. My biggest issue: The f'ing alternator doesn't work, battery is dead. So much for keeping the OEM ecu. The only think it's supposed to be doing fails. I'm off to NAPA to get one of those quick-and-dirty regulators.

How do you know? You mean, you look at how often the OEM pulses it? My idle valve is the loudest thing in the car. It vibrated the whole intake, you can hear it out of the air cleaner. It works great, but seems wrong. I gotta read up on that, right now I'm just happy to be idling, watching the battery slowly tick down.

AbeFM

iTrader: (3)

I know. Aren't I hot?

Oh! Now there's a picture. :-) My buddy was telling me (for reasons I cannot comprehend) that saturating the coils leads to weaker spark. Not sure I get it, but it does run very very well when you turn it off JUST before it gets there. It's where I set mine, adding in a half ms at a time. I'll revisit this when everything's running well.

Joe Perez

iTrader: (8)

Yes. Remember that current probe I showed you? I used that to measure one of the two wires going into my IAC and found that the current through it was being pulsed at 160Hz.

On MSI anyway, you enter the frequency as 10000/x for some reason. DIYAutotune puts 62 in that box (which equates to 161Hz) so I was basically confirming their observation. Should be easy enough to repeat this experiment on the MSII if you still have the stock ECU available to drive the IAC.

AbeFM

iTrader: (3)

Yeah - I might have to hook the OEM back up for that. I dunno. I used my leftover 50 mOhm resistor for measuring current on the dwell time on the coils and it worked out great, the pins were easy to remove on the coilpacks. I could likely do the same there. I've tried just wrapping wire about a line before, it basically doesn't work too well. :-)

Still, it's an open question to anyone if you know the right frequency to use for an '00 IAC, or have a reasonable guess.


Now, my real reason for posting: I HAVE NO TACH! I have no idea where to get a tach signal from, nor what the dashboard is used to seeing, or where it gets it. Someone MUST be running a stand alone. Maybe all I need to do is feed the tach the same signal I'm feeding the MS, 4 pulses per rev. Anyway, I don't care what or how, but having the needle just sitting there sucks - and I have NO idea how to start on this, though I guess I could get out the scope and trace the line, I'm hoping someone is just running a MS-stand alone, be it MS-I,or MS-II. If someone knows how to get the MS-II to put out a signal, all the better. I have more unused output circuits.

Other than that, yeah, it's idling, running the IAC valve (got the PID set up ok, but trying to get it to idle without it. It's working, but I don't yet know how to smooth it out), charging, and just generally "working". Stumbles like mad from like 2k-3k, so I have to look at the tables, but I'm not there yet and I'm falling asleep at the wheel. :-)

AbeFM

iTrader: (3)

Anyone know how the tacha and speedo work? They both go into the computer, then back out to the guages, and I found no docs on either. I don't even know which color wires go to which guage.

I can't imagine it's worth having the MS watch speed...

I guess there's a microprocessor IN the guage cluster, so I don't know where it gets speed from at all..... I have this nice tach circuit, but nowhere to feed it yet.

Reverant

iTrader: (10)

The microprocessor is in the small box behind the Odometer. The speed signal is derived from the speed sensor in the gearbox. IIRC the output signal from the speed sensor is 5V square-wave and the output frequency at 60mph is 133Hz. The tacho, I think 12V, square wave and output frequency at idle is in the 25Hz range (a complete pulse every 40ms on the scope).

Jim

AbeFM

iTrader: (3)

Ah, well, as long as the speedo is right off the tranny, I can ignore it. And I like ignoring things. :-)

The tach is more confusing. "Idle" on my car is 800 rpm. I shipped off the numbers to NASA and their super computer came back with:

800 rpm / 60 sec/min = '13 and change'.

Which means you're seeing a two pulses per revolution? That's weird! I could see four (just passing the crank sensor) and I could see 1 (passing the ignition pulse for channel A).

Hmmmm, ok, I guess it's any-time-a-cyl-fires.

Ok, well, even if the MS can't put that out on it's own, it'd be trivial to have an OR gate feed a transistor and put a 12V square wave to the tach. Weird it's 12 volts though. Maybe I could just watch the power line feeding the coils? Seems risky.

Joe Perez

iTrader: (8)

On the NAs, tach is active-high 1 pulse per ignition event or two pulses per revolution.

Can't see why it would be any different on the NB. Forget an OR gate, just use a pair of diodes. (ok, technically a pair of diodes is an OR gate...)