[rusEfi] 2001 Mazda Miata - Engine #46

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2001 Mazda Miata - Engine #46

Post by MgFoster » Wed Dec 26, 2018 3:39 am

First off, Merry Christmas and Happy New Year! My name is Matthew, I’m a Computer Engineering student at Georgia Institute of Technology. I own a 2001 Mazda Miata. I’ve had the car for a couple years now, and after a couple track days, some autocross, and sorting out the rest of the car, I decided I wanted to feed some boost to its stock 220,000-mile engine.
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My friend at school, you may know him as mck1117 on here and has a rusefi’d Volvo 240, convinced me to go this route when we were talking about engine management options. I, regretfully, purchased an UNASSEMBLED kit back in April. I figured I’m a Computer Engineering student, I can figure anything out. While I learned a little bit, it was just not worth the $100 savings to create that much extra work for myself. School, life, extra-curricular activities, jobs all got in the way of finishing it.
IF YOU ARE CONSIDERING RUSEFI PLEASE JUST BUY AN ASSEMBLED KIT
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But alas, 8 months later, and I’m using my time over the holidays to finish it up and hopefully have a first start before the new year! At this point, I think all of the on-board hardware has been finished, and I have successfully powered the discovery board while attached to frankenso, installed all the software, and connected to tuner studio without any explosions!
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Now I am starting work on the harness planning and had a couple questions for anyone running VVT miatas. Here’s what I have so far:
https://docs.google.com/spreadsheets/d/ ... sp=sharing

1: Is 3M the right pin on the NB2 harness for the exciter wire and where does it get wired to Frankenso?
2: Can you verify the IAC and VVT wiring is correct here?
3: Do you see any other glaring issues?

Thanks in advanced, can’t wait to be a runner!
Last edited by MgFoster on Fri Dec 28, 2018 6:29 pm, edited 2 times in total.

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Re: 2001 Mazda Miata

Post by russian » Thu Dec 27, 2018 1:25 am

Hello and welcome!

Have you seen

https://rusefi.com/wiki/index.php?title ... Miata_2003
https://rusefi.com/wiki/index.php?title ... Miata_2001
https://github.com/rusefi/rusefi/blob/m ... ta_vvt.cpp - you can use rusEfi console to get same exact settings as I have on my red test mule using set engine_type 55 command
?
alternator exciter would be one of the +12v pulled-up high side transistors
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Re: 2001 Mazda Miata

Post by kb1gtt » Thu Dec 27, 2018 10:31 am

Hello and welcome along. Congratulations on getting it to power up and keep the magic smoke inside.

I think your questions are mostly answered in @'s post. I'll comment about 3)

I suggest very modest boost, if at all. Boost pressure can cause detonation pressures, which can physically destroy an engine. Most turbo engines use a shorter piston to decrease the compression ratio. If you put on a turbo, or super charger, I would suggest changing the pistons as well. With out it, you are at a high risk of damaging the entire engine. If you change the pistons when boosting, you will have significantly higher chances of success. Also Once you add a turbo or super, that will change your Volumetric Efficiency (VE) and your OEM ECU will likely not work very well any more.

I suggest first getting it running under and OEM setup. I understand you can free up many HP's just by tuning it. These cars are geared for the low end to make them feel peppy. Freeing up some extra HP's will make it feel even more peppy. Simply getting it running huge undertaking, so take it in baby steps.

Also I believe you can run it without VVT. However it would not run very well, but I believe you can run it. I recall VVT opens up HP above some RPM. I believe you should be able to idle it and run it under moderate loads and moderate RPM's.

As for alternator control, like @ has noted, I think you'll need an additional circuit for that. We have developed a small board which can be added to the bread board area of Frankenso. Without this you run the risk of running your battery down. So keep the head lights off, and keep the electrical loads low. You can likely run the car just fine for like 30 minutes or if you have a good battery. If you are in the garage, it might be best to leave a battery charger on the battery, to emulate the alternator.

I recall there is a simulation option. I believe you can run this simulation, and see the LED's blink for your fuel injectors, etc. This helps ensure you have those MOSFET's and such installed properly.

Again congratulations on getting it powered up.
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Re: 2001 Mazda Miata

Post by MgFoster » Thu Dec 27, 2018 8:13 pm

russian wrote:
Thu Dec 27, 2018 1:25 am
Hello and welcome!

Have you seen

https://rusefi.com/wiki/index.php?title ... Miata_2003
https://rusefi.com/wiki/index.php?title ... Miata_2001
https://github.com/rusefi/rusefi/blob/m ... ta_vvt.cpp - you can use rusEfi console to get same exact settings as I have on my red test mule using set engine_type 55 command
?
alternator exciter would be one of the +12v pulled-up high side transistors
Thanks for the pointers! I totally forgot about those links... Ill double check all my work with what is found there.
Are you running MAF or MAP on the 2003?
Also, what are you doing with the immobilizer wire? Nothing? Jumpering to 12V?

Thanks again! Hoping for a running engine tonight!!! :D :D :D

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Re: 2001 Mazda Miata

Post by MgFoster » Thu Dec 27, 2018 8:19 pm

kb1gtt wrote:
Thu Dec 27, 2018 10:31 am


As for alternator control, like @ has noted, I think you'll need an additional circuit for that. We have developed a small board which can be added to the bread board area of Frankenso. Without this you run the risk of running your battery down. So keep the head lights off, and keep the electrical loads low. You can likely run the car just fine for like 30 minutes or if you have a good battery. If you are in the garage, it might be best to leave a battery charger on the battery, to emulate the alternator.

I recall there is a simulation option. I believe you can run this simulation, and see the LED's blink for your fuel injectors, etc. This helps ensure you have those MOSFET's and such installed properly.

Again congratulations on getting it powered up.
Thanks for the words of advice! I am absolutely going to get the ecu completely sorted first with the stock power-train.
As for turbo-ing, a blown engine wouldn't be devastating to me, and would just give me an excuse for forged internals :D

Alternator Control: @s post says to just wire the exciter to a high side transistor? Are you saying there is additional circuitry required to control it? I have seen the megasquirt guys have had to use a separate board for the alternator control, but I was under the impression our high side drivers and PWM control was enough.

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Re: 2001 Mazda Miata

Post by russian » Thu Dec 27, 2018 9:04 pm

I run MAP. I do not even know which wire is immobilizer.

Miata does not need extra board since logic level of alternator control. Dodge neon was the only vehivle to require high current high side driver.

For first run you need no MAP no alternator no idle no vvt :)
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Re: 2001 Mazda Miata

Post by kb1gtt » Thu Dec 27, 2018 11:12 pm

For clarity, I think @ is saying that for alternator control, you wire to the HI/LO driver, which is strong enough to drive the field. Is that correct?

I'm not sure if he's saying you do not need alternator control, as it's already done internal to the alternator. I think he's saying you need to control the alternator, but for now ignore it, and it's an easy fix after you have it running.
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Re: 2001 Mazda Miata

Post by russian » Fri Dec 28, 2018 12:38 am

kb1gtt wrote:
Thu Dec 27, 2018 11:12 pm
@ is saying that for alternator control, you wire to the HI/LO driver, which is strong enough to drive the field. Is that correct?
Correct.
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Re: 2001 Mazda Miata

Post by mck1117 » Fri Dec 28, 2018 8:08 am

It runs!



Started it with literally the bare minimum: power, cam, crank, injectors, coils, and fuel pump. Sensors are for the weak! Not even a wideband. Kicked on the first try after trying to get the trigger inputs to behave themselves.

Ran it fixed timing, alpha-n(without the tps hooked up) with the whole table set to 4ms or something. It was running super fat, but it ran super smooth so we know the trigger inputs and injectors and such all work.

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Re: 2001 Mazda Miata

Post by kb1gtt » Fri Dec 28, 2018 10:05 am

Congratulations. That's a huge step. Keep us posted as you get sensors and such features installed which make for a more drive-able system.
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Re: 2001 Mazda Miata

Post by MgFoster » Fri Dec 28, 2018 3:36 pm

She does indeed run! Encouraging to say the least. Not without our fair share of issues though.

We could not get the Crank signal to work through the dedicated trigger hardware. It was as if it was being filtered way too aggressively, even with the capacitors completely removed. Instead, we used analog inputs 9 and 11 for Crank and Cam, and things got a little weird. For the Cam, which was coming in on input 11, there was no option to select pin PC5 in tunerstudio, so we had to add another jumper to bring it back to PC6. Then for the crank on input 9, when we assigned it in tuner studio to be PA7 it seemed to completely break the firmware. We couldn't get anything to show up on the console at all. (Currently we have them jumpered all the way back to PA5 and PC6 and it seems to work just fine).

Next problem. I left all the jumpers W1-W64 off so that we could add in signals one by one. After installing the 4 injector jumpers and the 2 coil jumpers, the whole ECU stayed powered from the programming cable even after the car was shut off? The board would power off immediately if you unplugged the cable. What could this be caused by?

Thanks again! Guess I'm officially a runner!

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Re: 2001 Mazda Miata - Engine #46

Post by mck1117 » Fri Dec 28, 2018 11:42 pm

To echo the other Matthew's notes on trigger inputs: if you pick PA7 as the primary trigger input, it 1) doesn't work and 2) breaks the engine sniffer view. I even tried configuring the ECU with the tune from my Volvo (not connected to the car) and changed the primary trigger to PA7, which caused the same behavior.

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Re: 2001 Mazda Miata - Engine #46

Post by russian » Sat Dec 29, 2018 1:56 am

in rusefi_console messages it's supposed to be printing FATAL: followed by human readable error message

in Tuner Studio there is "error" gauge

is the message "input already used?" and error 6679? That one says that you cannot use PC6 and PA7 simultaneously since that's same TIM3 input capture unit.

All this remind me that https://github.com/rusefi/rusefi/issues/639 is an improvement I am thinking but have not yet created an issue for. Now there is an issue for it :)
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Re: 2001 Mazda Miata

Post by russian » Sat Dec 29, 2018 1:57 am

mck1117 wrote:
Fri Dec 28, 2018 8:08 am
It runs!
Heeeeeeey! It runs! Congrats :)
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Re: 2001 Mazda Miata - Engine #46

Post by mck1117 » Sat Dec 29, 2018 2:00 am

I got an error because some analog channel was trying to use PA7, but once we switched that to NONE it had no error. The trigger was the only thing using the pin, and I got no error or warning about using PA7 as primary, and PC6 as vvt cam sync or secondary.

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Re: 2001 Mazda Miata - Engine #46

Post by russian » Sat Dec 29, 2018 2:40 am

mck1117 wrote:
Sat Dec 29, 2018 2:00 am
I got an error because some analog channel was trying to use PA7, but once we switched that to NONE it had no error. The trigger was the only thing using the pin, and I got no error or warning about using PA7 as primary, and PC6 as vvt cam sync or secondary.
This is not about PA7 pin being used. This is about two pins being two channels of the same timer while you can only use one channel of each timer. If you use pin PC6 - you cannot use pins PA6, PA7, PB4 and PB5.

At the moment trigger and vvt and VVS system is not done the best way - at the moment we use "TIM in ICU mode" hardware where we only get few channels available. See above for ticket which points to the fact that we can either move to another hardware function to do the same or allow two options or else.
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Re: 2001 Mazda Miata - Engine #46

Post by mck1117 » Sat Dec 29, 2018 2:44 am

Gotcha. Still though, the ECU didn't throw an error that they were both trying to be used as timer inputs. Is that documented anywhere?

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Re: 2001 Mazda Miata - Engine #46

Post by russian » Sat Dec 29, 2018 2:58 am

mck1117 wrote:
Sat Dec 29, 2018 2:44 am
Gotcha. Still though, the ECU didn't throw an error that they were both trying to be used as timer inputs. Is that documented anywhere?
I guess I am still missing something. Can you please shoot a video showing what exactly you change and how exactly is ECU behaving? Including showing the four LEDs in the button area.
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Re: 2001 Mazda Miata - Engine #46

Post by russian » Sat Dec 29, 2018 2:58 am

PS: I've tried reproducing locally and I got red LED and error message on LCD and in console and in TS
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Re: 2001 Mazda Miata - Engine #46

Post by kb1gtt » Sat Dec 29, 2018 9:38 am

mck1117 wrote:
Sat Dec 29, 2018 2:44 am
Is that documented anywhere?
Do you have edit capability on the wiki? If you get edit capability, is there any chance you might create documentation similar to this? Our documentation is weak, it would be great if someone with hardware created a start to finish video, or wiki page's, or some kind of documentation.
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Re: 2001 Mazda Miata - Engine #46

Post by MgFoster » Sat Dec 29, 2018 5:49 pm

Wiki editing is something I would love to contribute to at some point. I think documentation is what’s preventing more people to try rusEfi.

@ do you have any insight to why the board would stay powered through the programming cable?

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Re: 2001 Mazda Miata - Engine #46

Post by russian » Sat Dec 29, 2018 6:08 pm

MgFoster wrote:
Sat Dec 29, 2018 5:49 pm
Wiki editing is something I would love to contribute to at some point. I think documentation is what’s preventing more people to try rusEfi.
Let's move this discussion to viewtopic.php?f=13&t=1465
MgFoster wrote:
Sat Dec 29, 2018 5:49 pm
@ do you have any insight to why the board would stay powered through the programming cable?
"programming cable" is vague - there is firmware flashing cable and there is ECU setting changing cable. I assume Discovery? So, mini USB or micro USB on discovery?

Also there is a good chance I experience the same and just live with it. Also I am only a software guy, I know there is GND and +12 volts and that's the edge of my electronics skills :(
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Re: 2001 Mazda Miata - Engine #46

Post by mck1117 » Sat Dec 29, 2018 6:09 pm

Yep, micro USB on discovery.

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Re: 2001 Mazda Miata - Engine #46

Post by russian » Sat Dec 29, 2018 6:13 pm

mck1117 wrote:
Sat Dec 29, 2018 6:09 pm
Yep, micro USB on discovery.
I think I just leave with it.
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Re: 2001 Mazda Miata - Engine #46

Post by kb1gtt » Sat Dec 29, 2018 7:40 pm

I recall that one of the USB connectors will accept 5V from the USB, which might have a blocking diode. I recall it powers the discovery, but not the PCB, or perhaps it does, and if we remove a diode it doesn't or something like that. If you are concerned, I think the discovery has a diode or jumper which can be installed to prevent the USB from powering the brain board. However if you do that, then you'll need 5V provided by something else like the 12V regulator.
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Re: 2001 Mazda Miata - Engine #46

Post by mck1117 » Sat Dec 29, 2018 7:41 pm

I helped out with the first start because I was in Atlanta anyway, so I can't look at my own disco board, but I THINK I removed one of the diodes on that end of the board. I'll take a look on the 31st.

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Re: 2001 Mazda Miata - Engine #46

Post by russian » Sat Dec 29, 2018 7:42 pm

mck1117 wrote:
Sat Dec 29, 2018 7:41 pm
I helped out with the first start because I was in Atlanta anyway
That explains a lot, I was a bit confused about the logistics of this first run :)
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Re: 2001 Mazda Miata - Engine #46

Post by MgFoster » Sun Dec 30, 2018 6:29 am

I've been noticing that it doesn't stay powered through that cable every time. Can't quite put my finger on what causes it to, but I *think* it might be only after attempting to start, or starting.

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Re: 2001 Mazda Miata - Engine #46

Post by MgFoster » Sun Dec 30, 2018 7:03 am

Tonight was very productive. I have a MAP sensor, IAT, CLT, IAC Valve, fans working, Alternator exciter working, and TPS sort of working.

I guess I'll spoil you guys with the good videos first....
https://www.youtube.com/watch?v=bYK3fkSYcsE
It runs awesome! I still need to hook up the wide-band :shock: (first on tomorrows list), but I used @'s tune from his 2003 and it works. Definitely rich, but oh well.

Now on to the discussion..... The TPS signal is wild. I'm hoping @ can help me out in the hardware department.
Screen Shot 2018-12-29 at 5.18.51 PM.png
Screen Shot 2018-12-29 at 5.18.51 PM.png (52.19 KiB) Viewed 1159 times
First off, all of my resistors in this circuit have been checked and are correct.

In this first video, I actually had no C251 installed (oops) and an unknown value cap at C250.
https://www.youtube.com/watch?v=MOY2QrTEceI
You can see, it was all over the place. Like bad. Sometimes did what it was supposed to, sometimes didn't. and it was sometimes realy slow to respond. I attribute this to the lack of C251?

Video 2: https://www.youtube.com/watch?v=1oQgRCcQg8o
In this video, I installed a .01uF cap at C251 (because I couldn't find anything closer to .1) and a .01uF at C250.
You can see it was slowly rising on its own, then I blipped the throttle a couple times, it returned to zero, but right at the end of the video, it started to rise again.

Video 3: https://www.youtube.com/watch?v=_cJ2GItqAjM
I think this was the same config as video 2. Literally just oscillating on its own.

In the end, I completely removed C250, and I still have the 0.01uF cap at C251. It sometimes behaves, but if I leave it floored (TPS at 100%), it begins to fall.

Could the wrong valued C251 cause this??? i get that a factor of 10 is a pretty big deal, but it just seems so intermittent.

I would like to see a video or hear about the behavior of the TPS ADC value on @'s and @'s cars.

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Re: 2001 Mazda Miata - Engine #46

Post by kb1gtt » Sun Dec 30, 2018 11:09 am

Can you post a picture of your op-amps? I'm specifically looking to verify you have a microchip,MCP6004-E/SL installed, and your solder joints are good. As well I'm looking to check W51.

The C251 is a fairly generic bulk cap. It's primarily there to prevent high frequency stuff from being pulled across the PCB. AKA the op-amp is a high bandwidth device, it will generally try to consume perhaps even MHz's even for a low frequency signal. When it tries this, that energy comes from this local cap instead of across the PCB. If you negated C251, I would guess you also negated C211 and C291. Try adding those caps and see if that helps. AKA remove the high frequency's generated by other things could help avoid RF from getting into this one.

I believe you said the saw tooth pattern went away when you installed C251, so I'll ignore that video. The wandering in Video2 is the one I'm most concerned about. I wonder if D250 could have some leakage, or perhaps there is a bad connection in the TPS circuit some where. There is also a possibility of high frequency content which is not seen on the low frequency TS gauges. Here are some questions.
-- Can you connect a multi-meter to the TPS and measure the voltage at the harness connector?
-- Do you have a scope? Can you look for higher frequency content at the connector, or other places in the circuit?
-- If allowed to wander, does it go to 100%, or perhaps it goes to 50% given time. Where does it wander to?
-- If you disconnect the TPS from the harness, does it still wander? Perhaps remove W51 to disconnect it from the harness.
-- Am I correct that you have nothing connected to INP6 to INP8? I think TPS is the only thing on this op-amp. Is that correct?
-- Do you have R281, R271 and R260 installed? If floating those could be high frequency oscillating. These resistors would prevent other circuits from causing problems with this one in the same op-amp chip.
-- Do you have C260, C270 and C280 installed? Again oscillation potential on the shared op-amp.
-- Same for R264, R265, etc. With no load resistors, it can cause other op-amps to oscillate.

Do I recall that there is an option in the console which allows a semi scope like feature? I recall you can get the console to display or provide the analog data as fast as the ADC and serial stream can provide it. Perhaps that can provide information about the TPS, or other analog signals.
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