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Official LH2.4 EZK Wasted Spark Conversion - Installation Instructions

I used the miata amp in my car and it worked just fine on the stock tac. If I remember correctly there is a pullup wire you may have to splice in as well to get your particular tach working properly. I'm gonna go look at my notes from when I ran mine

Please do...it's a freshly restored R-sport cluster, so it's doubtful I have a issue with the tach.

Tested for continuity from wire at gauge to igniter...that's fine.
 
What a surprise...the TACH output on the Miata J702T igniter is (+)...it pulses like a tach should, but it's (+) not (-)

Rewire tach to get constant (-) and let the (+) pulse trigger it?

Has anyone successfully driven a Volvo Tach with this?
 
K...I was wrong.

I have a proper (-) tach signal...but it's only 2v....

My 245 with stock ignition has 10v for a tach signal....seems the issue is signal strength.

Is this how all J702T tach outputs are, or is mine broken?

I suppose I could drive a ignition amplifier but that seem excessive.

Someone must have crossed this bridge before me.
 
I used the miata amp in my car and it worked just fine on the stock tac. If I remember correctly there is a pullup wire you may have to splice in as well to get your particular tach working properly. I'm gonna go look at my notes from when I ran mine

I attempted a 10k resistor, pull-up wire...didn't get the tach firing.
 
BUCHKASPARK.jpg


Can you elaborate on this for the electronically challenged like me?

Does it work like this?

<a href="http://s338.photobucket.com/user/turbobrickspics/media/Dummycoil_zpsb5ad7d52.jpg.html" target="_blank"><img src="http://i338.photobucket.com/albums/n413/turbobrickspics/Dummycoil_zpsb5ad7d52.jpg" border="0" alt=" photo Dummycoil_zpsb5ad7d52.jpg"/></a>

That's exactly how I did it. It's the same circuit that's listed on msextra.com.

photo.JPG
 
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Solved the problem about my NO TACH...it was due to a faulty J702T igniter...

I dug up my old spare, and swapped it in....tach works perfectly!

So, to confirm, the J702T will directly drive a Volvo tach....with no use of a relay coil or pull-up wire...but your J702T igniter has to work.
 
Solved the problem about my NO TACH...it was due to a faulty J702T igniter...

I dug up my old spare, and swapped it in....tach works perfectly!

So, to confirm, the J702T will directly drive a Volvo tach....with no use of a relay coil or pull-up wire...but your J702T igniter has to work.

Hello
Can you please post some pictures of the J702T setup in the car?
Would be nice to see it... :-)
 
So I got a board in the mail today from another tb'er, and I've got a harness built for my VAG coils, and ipdown's program to setup the dwell for these coils. Going in either tonight or tomorrow, but I gots a Q.
I'm going to keep my stock coil set up, and use a switch chip with stock setup, so if I need to I can just switch back to the dizzy if the need arises. Can I just use the switched 12v for the stock power stage for my coils, and split it between the two? Or if not, what's the best switched 12v to tap into?

Eh, looking at a diagram makes it seem like the stock power stage shares switched 12v with several others anyways, so I'll run it there.
 
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I got the board soldered up yesterday, and installed with coils today.

No start. Now the coil and dizzy were still in place, and the car will run if I just hook up the spark plug wires.

From the stock coil, I have a bright blue spark, and with those wires hooked up I have a thick, bright blue spark at the plug. With wasted spark coils hooked up, I have a weak, yellow spark.

I built the harness using AWG 16 wire for switched 12v and grounds, and 18 gauge for logic level spark outputs.

I tried with ground to engine block, and grounded to battery; tried with power from switched 12v at several different locations, and then just power straight from battery while cranking. No change.
I pulled the ecu back out and double checked solder. The board has 5v power and good ground; I believe the VR signal is good because if I swap the outputs I start getting fire 180 degrees out, engine speed picks up, etc. My balancer is off a little right now so I can't check with a timing light.
Measuring at the logic level outputs, I'm getting a signal but maybe it's not strong enough? Or maybe I just need to redo my harness.. I'm completely unsure and a little frustrated, I was ready for my car to fire off on those coils!
Help?
 
Still no fire. So I rebuilt the harness with 10 gauge wire for the 12v and ground circuits, with the 10 gauge tied to the positive terminal and run through a relay that is controlled by switched 12v from the diagnostic port.
Then I tested resistance on the coils individually, and compared that to resistance from the connections to logic level outputs, and I have continuity through those circuits. So I tied signal ground to the EZK's internal ground, no change.
I tested the board with a DVOM, and I've got 5v to the board, and a good ground, which leads me to suspect the spark output. I believe it should be a 5v output, but I'm only getting around .3v to the board. I read here http://www.atmel.com/Images/doc7607.pdf that minimum output high voltage for the Atmega controller is 4.0v, so it should be sending 5v to the coils, but it's not.
So I think I might either a bad board or a bad solder to the spark output on the EZK; I'll check it in the morning.

So I looked and the IC on the board is attiny24a, and its dc characteristics are listed here

http://www.atmel.com/Images/8183_105.pdf

The attiny24a needs to see .6v to pull the circuit high if supply voltage is 2.4-5.5v; from the spark output, tested on either side of the resistor and at the wasted spark board, I'm only getting about .5v. The wasted spark board is outputting .3v consistently on both spark outputs. I don't think I'm going to get any fire out of that. Something strange is going on...
 
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It works!! Thanks to ipdown for helping me figure it out. Karl's board uses NPN transistors to switch the coils' path to ground; these VAG coils I'm using have to use PNP transistors to switch a 5v power feed. So I went to radioshack, got a few transistors (2n3096 I believe), a few 1k ohm resistors, and a small round pcb to mount them on.



I fed the spark output signals from the wasted spark board through the resistors and into the new PNP transistors, 5v through the emitter and then ran the output to the coils from the collector. Now Karl's board switches the path to ground for the PNP transistors, and those feed 5v to my VAG coils.



And after that whole mess, I had the leads coming out of the EZK box switched, so I was a little angry at first... switched the output leads and she fired right up!
 
Is it possible to order this "buchka boards" for volvo b230(fk) ?
I live in Norway..
PayPal is fine...
 
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