[rusEfi] red 2003 VVT test mule Miata NB2 #27

What engine are you torturing? Is it inside some car?
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AndreyB
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Re: red 2003 VVT test mule Miata NB2 #27

Post by AndreyB »

But even with not eBay coils I have crank signal disappearing if coils are hooked up :(

Here you can compare second line signal with both coils disconnected VS one coil connected.
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Re: red 2003 VVT test mule Miata NB2 #27

Post by puff »

hm. shall I try cranking my oldrusty rover without a coil attached?
do you think it's just affecting the usb connection, or the whole thing?

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Re: red 2003 VVT test mule Miata NB2 #27

Post by puff »

one more thing, I've heard that installing a large capacitor across the coil's power lines help (although I don't understand why it should help)

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Re: red 2003 VVT test mule Miata NB2 #27

Post by kb1gtt »

Yeah, it's likely a huge inrush, causing the GND voltage to spike. The huge cap on the supply simply provides allot of HF energy locally, so you don't have that energy on the MCU GND.
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Re: red 2003 VVT test mule Miata NB2 #27

Post by AndreyB »

After 24 hours of head banging I've noticed that cranking RPM without coils was 480 RPM. 480 RPM is not the right cranking RPM of my car, it should be 240 RPM...

Now I am thinking that there were multiple issues introduced at different points in time - loss of GND during the catastrophic event, bad replacement coil was not helping and on top of that wrongly "refactored" VVT or trigger code has messed up engine cycle :(

Test mule now starts reliably on MRE 0.3 - if 2019 Xmas firmware is used AND there is a jumper cable between engine block and battery.

Also note how on this picture VVT fronts are inverted comparing with 2019-10-21_rpm_1102_Frankenso_MAX9926_5K_pull_ups.png in first post of this thread.

I will go have some cognac.
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