[rusEfi] Mazda MX5 1.8 1999 AE (#4)

What engine are you torturing? Is it inside some car?
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Re: Mazda MX5 1.8 1999 AE

Post by sturovo » Sun Apr 13, 2014 7:23 pm

Some progress!

It runs :D
[video][/video]

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Re: Mazda MX5 1.8 1999 AE

Post by rus084 » Mon Apr 14, 2014 10:37 am

when you will tune it for driving?

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Re: Mazda MX5 1.8 1999 AE

Post by sturovo » Tue Apr 15, 2014 7:35 pm

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.
Image

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.
Image

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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Re: Mazda MX5 1.8 1999 AE

Post by russian » Sat Sep 13, 2014 6:19 pm

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/F ... pinout.jpg for the location of the VP pin.
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Re: Mazda MX5 1.8 1999 AE (#4)

Post by sturovo » Sun Sep 14, 2014 4:38 pm

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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Re: Mazda MX5 1.8 1999 AE (#4)

Post by russian » Sun Sep 14, 2014 5:02 pm

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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