[rusEfi] 1994 USDM Mazda Miata #11

[spags]

Hi,

Idea #1 and #2 will be tested tomorrow.
Idea #3, no cold welds as far as I could tell on the ignition drivers. Traced everything down to the stm board pins and out to the breakout area. Ground works, one curious thing is I found continuity between the 12V_CONST line on the connector to Vdd _AND_ GND. No idea if this is normal. The LED's will tell us what is going on for good.

Also, while checking things, i noticed a loose strand of copper fall out of the board. Who knows that could of been it. Nothing seems damaged or smells funny.

Re: The car does have an alarm, but at this time I'm don't think the alarm is part of the problem.
1 - Not sure it that was the alarm. Zeb (the guy doing the cranking was fiddling with my steering wheel, momo....hmm....sexy)
2 - It didn't repeat itself with other cranking tries. No issues with the alarm the rest of the time on the stock ecu, this car is my daily driver (I have spares)
3 - This car ran on a DIYPNP for a few months without any issues with the alarm. Also we didn't notice any other subsystem affected by the alarm (fuel pump for example).

As for the cranking; I did check the battery wires after the 30 second crank, they where hot to the touch but not unbearable, In any case I agree cranking the car for that long is not a good idea. At that point I was trying to discard the car's electrical system as a suspect for the bad cranking while fueling.

[AndreyB]

Pin PE14 goes to high-side which goes to W7 on the board which is ECU pin 1G which is "Coil Pack Cylinder 1&4"

Pin PC7 goes to high-side which goes to W8 on the board which goes to ECU pin 1H which is "Coil Pack Cylinder 2&3"

This was upside down in the mazda_miata.cpp, thank you @ for pointing out the issues. Rumors are the car has started right away once the config was fixed

[spags]

It runs, as russian mentioned the final trick was inverting the pins. It started right up, while cold no less. The maps need work but where a great start. Got a nice solid idle. It smelled rich. What led me to the problem is that I ran sparkbench and got no spark on cyl. I heard one of the coils working and pulled out the plug for cyl 2. Lo and behold I got a spark. At that point it was a simple pin reassignment and it started right up. Should of done a sparkbench test from day one. Live and learn.

As for the spark not working while cranking. Maybe it was a wild goose chase or maybe that copper strand was the reason, no way to know

There was one casualty:I knocked the big capacitor next to the connector on it's side while disconnecting it from the car. No biggie, it can be easily soldered back.

Also found my car will idle very nicely using 300 as the PWM load. (set_idle_pwm 300)

So, whats next? I'm going to make separate posts for these items as work progresses but here is a short and possibly incomplete list:
Cluster tachometer has to work.
Wideband O2 sensor, this is a must for any aftermarket ECU, rusefi is no different. I have an opening on the ECU plug. Still debating how to do this.
Radiator fan needs to work, since I live in the outskirts of hell this is a must if I want to run this on my car.
Humming noise while the car runs, drives me bonkers. Maybe the PWM frequency on the ICV is not high enough and the solenoid jiggles? Funny thing, it doesn't hum nearly as loud when the engine is not running but in the ON position.
A/C, this will need some changes to the idle code.
World domination, that _IS_ what we are doing here, right.

Anyways, without further ado. Here are the videos.
http://www.youtube.com/playlist?list=PLyPvY2Eq9L9O7nKx8C8vgV7BlF9NxJjQU

I've attached the logs as well for your data munching pleasure.

[AndreyB]

Re: case
http://rusefi.com/wiki/index.php?title=Manual:Hardware:Mazda_PnP#Case_Donor

[AndreyB]

Cluster tachometer has to work.

Hm.
As funny as it might sound, tach signal is generated by the coil pack - see BLK/WHT wire at the left-bottom corner of http://www.rusefi.com/wiki/images/2/2b/1994_miata_1.8_3.png

However this wire does go into the ECU and looks like it's R541 which is a 2K pull-up to +12v.

Step 1: open stock ECU case, with ignition ON measure voltage on pin 2I. Luckily for us that's the top row so it's easy to touch this wire where is says 2I on the oem PCB. If this in fact shows +12v then probably (on your own risk, sorry) you can proceed to
Step 2: add some pull-up resistor in the 2K range to +12 wire?

It would be fun if that would give you a working tach gauge.

[spags]

After a bit of hunting for the right pin. I confirmed a healthy 11.55 volts on that line. Will rig something up tomorrow for testing.

Same for grounding 1L to test coolant fan relay activation.

[kb1gtt]

I'm going to recommend you hesitate for a minute about the 2I pin, it probably has some significant voltage spikes. Let me look into this before you install the 2k ish resistor.

[spags]

Ok, holding off.

I know that the 94-mid95 models had a different arrangement with how the tachometer was fed. They use a signal directly from the coils. Trying to compare notes with other aftermarket ECU's to see how they set it up. Since it's something that happened during 1 model year it's relativlely rare.

[deviator]

Humming noise while the car runs, drives me bonkers. Maybe the PWM frequency on the ICV is not high enough and the solenoid jiggles? Funny thing, it doesn't hum nearly as loud when the engine is not running but in the ON position.

Is it the same one I had? http://rusefi.com/forum/viewtopic.php?f=3&t=662&p=12363#p12312 This solved it for me.

[spags]

Confirmed... no noise with set_idle_pin off, and I have a diode.

My current theory is that the frequency of the PWM signal is to low and the solenoid jiggles a bit instead of holding. I saw this back when I had a MS. Have to dig up the discussion, but the issue was that.

Also, confirmed grounding 1L activates the coolant fan.

Still the tach signal is pending but i'm holding off until kb1gtt has a closer look.

EDIT: My PWM frequency theory for the idle control valve is totaly unsubstantiated, i don't know what frequency we are using and I can't remember what the stock ecu frequency was. Just hoping somebody that knows more than me discards it or makes it worthy of further inquiry.

[AndreyB]

Also, confirmed grounding 1L activates the coolant fan.

Perfect! Please add a wire between the corresponding breakout to E6 transistor breakout. Please check me, but looks like upper W12 hole to lower unnamed hole between W37 and W39

[kb1gtt]

russian notes that there was some other web page or something that confirmed the 12V thing for tach was OK. That works for me, and I hear it works. So I understand the tach thing is resolved.

[spags]

Yeah, found a few pages for other EMS's. The clearest one was:
http://www.miataturbo.net/aem-59/ems-4-tach-setup-60653/

So I slapped a 2.2k ohm resistor I had laying around as a pullup to +12v and it works beautifully. Will change that to a 1.8K (don't have any 2k ones laying around) and see how it goes.

Still have to tidy up before calling it done.

That's 2 items off the list. Next up is finding what is causing that ICV hum and confirm that the a/c lines do what I think they do.

I've also ordered a case and a wideband so I can start actual tuning when I get those.

[spags]

Have an issue with fan control. Will have more time to hunt it down later but in the mean time i'm posting it here.

Issue: Fan is on all of the time. fanbench has no effect.
What I did:
I followed russian's instructions here: http://rusefi.com/forum/viewtopic.php?f=3&t=729&p=12375#p12375
This is a pic of the wiring (maybe it's wrong ): https://drive.google.com/file/d/0B-T5j-1DVQnaNUVuRG9ERmVKQUxwandkQnVhTGFvUW5jenRZ/view?usp=sharing
I'm running firmware revision 5396

I will probably have some time to tidy that up later tonight and test again.

Re: Tach
The tach reading is high by a about %5. Will see what running 1.8k does.

[AndreyB]

Tach: I bet nothing would change with a different value - it's a digital signal, it's either there or it is not. Also my own experience is that analog tach (OEM gauge) is off comparing with digital tach (aftermarket shift light)

coolant fan: let's see if that's a hardware or firmware issue
step a) update to latest firmware
step b) invoke tempinfo command and post result here

it's expected to show what the firmware thinks about the fan state.

[spags]

Ok, tested. Everything seems to be working. The fan engagement temp was 75C and my engine was not cool enough. Eventualy, everything cooled down and I got to test engagement and disengagement.

Here is a sample output of the command:

Code: Select all

2014-11-16 20_50: PortHolder: Sending [sec!8!tempinfo]
2014-11-16 20_50: EngineState: confirmation_tempinfo:8
2014-11-16 20_50: EngineState: CLT v=0.92454 C=89.60513 R=612.51123 on channel 12
2014-11-16 20_50: EngineState: bias=2700.00000 A=0.00250 B=0.00000 C=-0.00000
2014-11-16 20_50: EngineState: @PC2
2014-11-16 20_50: EngineState: CLT R=612.51123 on channel 12@PC2
2014-11-16 20_50: CommandQueue: got valid conf! tempinfo
2014-11-16 20_50: EngineState: IAT v=1.26153 C=74.01892 R=911.11114 on channel 11
2014-11-16 20_50: EngineState: bias=2700.00000 A=0.00250 B=0.00000 C=-0.00000
2014-11-16 20_50: EngineState: @PC1
2014-11-16 20_50: EngineState: IAT R=911.11114 on channel 11@PC1
2014-11-16 20_50: EngineState: fan=Yes @ PE6
2014-11-16 20_50: EngineState: base cranking fuel 5.00000

I have to find some authoritative source for what the engagement temps are on the stock ecu. I'm sure they are higher.

So, confirmed, tach and coollant fan work.

Yay!

[kb1gtt]

I believe 180F to 190F is a common temp for thermostats. I would think turn on at 210F and turn off at 195F would be a good starting point guess.

[spags]

Yeah, those temperatures look reasonable, would like to make sure the calibration for the CLT sensor is sane (it looks that way?)

As for the humming sound, here's some info
http://forum.miata.net/vb/showthread.php?t=172015

I peeked at the code and the miata runs at 160 (Hz?); the stock ecu runs at 500 Hz and runs it through a low pass filter to make the wave form more friendly to the solenoid.
I think it would a good start to at least try and emulate that. Going to try this later this week to see how it goes.
Please stop me if i'm obviously going to break something!

[kb1gtt]

I should also add a comment / request that the fan on and off set points be programmable via TS. I know at least one hill climb driver that wanted the fans to turn on at a lower temperature. I think he now just uses a toggle switch, and leave the fan running during the climb to prevent that issue again.

[AndreyB]

I should also add a comment / request that the fan on and off set points be programmable via TS.

Already in the TS config

Code: Select all

	dialog = fanSetting, "Fan Settings"
		field = "Fan On Temperature",					FanONTemperature
		field = "Fan Off Temperature",					FanOffTemperature		

[spags]

Good news everyone.

The humming noise is gone. Sounds like a stock engine. Setting the ICV solenoid frequency to 500 did it. Mine board has a diode an from what I read elsewhere that is a really good thing.

set_idle_solenoid_freq 500
writeconfig
// restart the board
// start your engine and enjoy that oh so sweet puring (except I have HLA's that tick like a bad hardrive, but that's not the boards fault)

This fix should apply to all NA and NB miatas. From what I've read 500 is the frequency the stock ecu uses.

Interesting fact: The humming noise was NOT the ICV, it was a resonance caused by the icv that happened in air box. So it came from the wrong side of the engine, that threw me off.

Caveats:
This is not tested, although I noticed the neon has the same frequency.
This is not tested, will wait for the engine to cool down and run the ICV at that frequency for a few minutes to see if it heats up or explodes or forms a black hole and really cool shit comes out, like a pegacorn an shit.. I digress. Stay tuned will report back the results.

[AndreyB]

Yes but no. Maybe. Interesting. Weird

set_idle_enabled 1

would enable that naive algorithm which would try to hold idle @ targetRpm - see
set_idle_rpm 900

[spags]

I tried those commands. No effect. Holds an idle of 1600 without any changes.
It responds to set_idle_pwm just fine, and I can make it hold an idle of around 900.

Still have to test that the solenoid is ok with these settings, haven't checked anything yet, the car has not had a chance to cool down.

Will continue testing later.

[kb1gtt]

Can you measure the DC ohms of you IAC? In this thread http://rusefi.com/forum/viewtopic.php?f=3&t=666&start=50 we measured the ohms to be 12.1 ohms and we measured the OEM ECU to use a Duty of 250Hz. From those scope readings, I want to measure the time constant of the charge / discharge cycle, then predict the impedance (equiv of AC resistance which adds to the DC resistance) . Any how, I suspect we are dealing with different IAC sol so I wonder if yours measured close to 12.1 ohms or not.

[spags]

Ok, did some testing.

Got 12.0 Ohms across the ICV solenoid.

Ran it for 30 minutes at a duty cycle of 400 with a frequency 500. The engine was off and cold. The solenoid got slightly lukewarm, no strange sounds.

[spags]

Quick update,

I got a case for the board, it needed some modifications but it works like a charm.

The idle control works.
Russian has to make some changes to the code to make it straightforward. But when everything is said an done. This should work:

Code: Select all

set_idle_rpm 900
set_idle_enabled 1

Right now it's all kid of messy but it works!
I added some loads to the idle, like head lights and power-steering and it compensated. Slowly but it compensated.

Next items:
- WBO sensor so I can actually tune the things. The WBO will be installed next week, putting it in the midpipe. Will make a separate post detailing the modifications to the board.
- Verification of what does what in the A/C. This is the first step towards getting functioning a/c. After ecu us tuned.
- Tuning idle and cranking. It's still a fight to turn the engine on, no way to fix anything until the WBO sensor is installed.
- Tune and drive this thing!

[AndreyB]

I still need to write some code for the A/C switch, but in the meantime can you wire the harness A/C pin to the lower pad of W50? That's analog channel 6 - goes to PA1, it's set for a switch with a 10K pull-up R260.

[spags]

I want to test that the A/C lines do what is expected from the schematic before connecting them to the board.

Using this http://www.miataforumz.com/1990-200-Miata-Wiring/94sys.pdf as a reference. I want to test, another one of the miatas on this board reported his wiring didn't match to the schematic for some lines.

Inputs:
Heater Control (1S) - No idea what it does, my theory is it goes high when the heating is turned on in the console. Will measure it with A/C off, A/C on, A/C heating.
A/C enable (1Q) - Requests the ECU to turn on the a/c subsystem. Should read 12 volts when the a/c system on. 0 when A/C is disabled.

Outputs:
Compressor enable (1J) - When grounded compressor should engage.
Cond. Fan enable (2S) - When grounded condenser fan should engage.

Which one goes to W50?

[AndreyB]

Inputs:
Heater Control (1S) - No idea what it does, my theory is it goes high when the heating is turned on in the console. Will measure it with A/C off, A/C on, A/C heating.
A/C enable (1Q) - Requests the ECU to turn on the a/c subsystem. Should read 12 volts when the a/c system on. 0 when A/C is disabled.

Which one goes to W50?

Now I do not know I was hoping that there is just one input - the button. If we have two inputs, it looks like we need to figure out what they do. Anyway, I guess W50 would be the button regardless. I am assuming the two states of the button are disconnected and ground.

[puff]

it seems there is just some tricky logics in all these inputs/outputs: when the AC is on, the RPM usually increases (do not know the reason though - the newer -EFI- range rovers had such feature, as probably had toyota and may be something else), plus the fan turns on at lower temperature with AC on, and at higher - when AC is off (at least, AFAIK old audis had two-positions thermo-switches)