[rusEfi] Mazda MX5 1.8 1999 AE (#4)

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sturovo
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Re: Mazda MX5 1.8 1999 AE

Post by sturovo »

Some progress.

I downloaded the source and tools needed to compile resefi.hex and updated the relevant mx5 configuration file to reflect my i/o assignment.
After loaded the new hex I did some basic testing and tried to start car! There were a few ignition pops on the first try but none on subsequent tries. It looked like like no fuel was getting to the rail.
It turns out that OUT1 (where I have the fuel pump connected) needs a zero ohm resistor on the board to become active. I added the jumper and tried again. The results were a bit better with several ignitions occurring in a row. I adjusted the cranking fuel pulse width command and changed the global trigger offset angle a little but soon after my battery died.

Is there a console command that can be used to energize/toggle the coil channels for a short duration?
Also commands for toggling other outputs like fuel pump and injector channels would be useful when initially testing.

The learning experience continues. :D
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kb1gtt
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Re: Mazda MX5 1.8 1999 AE

Post by kb1gtt »

Very cool, very cool. Seems we have two spit fires now :)
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AndreyB
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Re: Mazda MX5 1.8 1999 AE

Post by AndreyB »

Fuel pump - on reset, it turns of for 10 or smth seconds, you would hear that.

Please take latest version, one of the commands is new:
fuelbench 20 50 3
This would turn FUEL #1 channel for 20 ms, keep it off 50 ms, repeat 3 times

sparkbench 20 50 3
This would turn SPARK #1 channel for 20 ms, keep it off 50 ms, repeat 3 times
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sturovo
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Re: Mazda MX5 1.8 1999 AE

Post by sturovo »

Some progress!

It runs :D
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rus084
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Re: Mazda MX5 1.8 1999 AE

Post by rus084 »

when you will tune it for driving?
sturovo
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Re: Mazda MX5 1.8 1999 AE

Post by sturovo »

As can be heard in the video the exhaust is currently open. My plan is to install a larger turbo and finish the exhaust before continuing with ecu testing. Hopefully by next week it will be ready.

I compared the stock ecu start data to the console start data. I used an Saleae type analyzer to grab data for cam, crank, both sparks and injector 1.
stockeculog_zps7b39923e.png
stockeculog_zps7b39923e.png (601.64 KiB) Viewed 7867 times
The global trigger is as expected during a start with the stock ecu. The spark coincides with the crank pulse immediately before the single cam pulse as shown by the red line. The ignition pulses with the stock ecu start out long but shorten within a few revolutions to about 10 milli secs. Also interesting to see how the injection switches from 2 injections per revolution one injection per 2 as the engine fires up. What is even more interesting is that RusEFI has a similar feature already implemented . :)

This was a snapshot from the console when running on Frankenstein.
2014-04-0913_04rpm_409_maf_207_zps41b3b14d.png
2014-04-0913_04rpm_409_maf_207_zps41b3b14d.png (199.49 KiB) Viewed 7867 times
The spark is coming a little late when compared to the stock ecu in this instance. Small adjustment of the global trigger offset and ignition offset improved how the car was running. Looking at the data it probably makes sense to first reduce the coil dwell time from 30 to 10 milli secs before adjusting the offsets further.
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AndreyB
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Re: Mazda MX5 1.8 1999 AE

Post by AndreyB »

Image

Have a question about your ignition control. I see you are using the "high/low" side chips for that, where is your VP line connected? Is it connected to +5, is it connected to +12 or is it left unconnected?

See http://rusefi.com/images/Frankenstein/Frankenstein_v011_pinout.jpg for the location of the VP pin.
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Re: Mazda MX5 1.8 1999 AE (#4)

Post by sturovo »

Andrey, The stock 1999 MX5 coils are triggered by +12v. As far as I know all 89 to 2006 cars (and possibly later?) were like this. http://forum.miata.net/vb/showthread.php?t=354300
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AndreyB
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Re: Mazda MX5 1.8 1999 AE (#4)

Post by AndreyB »

sturovo wrote:As far as I know all 89 to 2006 cars (and possibly later?) were like this.
Yep, that seems to be true. I am an idiot - I've realized that I had this picture all that time and I did not notice that it is +12v, not 5v:

Image

Funny thing that discovery input pins seem to be surviving this +12v input.
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