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Official LH2.4 EZK Wasted Spark Conversion - Installation Instructions

Hi guys. Unfortunately I have to add myself to the no startup list after installing my WS board. (Black WS board, only purchased a few months ago).

My symptoms are only an occasional pop as the car cranks. There is a spark but its very weak.

From what I've observed my logic level output from the WS board is very low, for the most part between 0.5 and 1v per channel as it cranks. That seems to result in erratic and short switch on/charge time for the coils, hence the weak spark.

Ok I'm pretty experienced at auto electrical wiring, so I'm confident I've got it all wired up right, including having the WS board outputs reversed. I've installed the WS board in two different EZK boxes with the same results. I've checked the wiring in the EZK to the WS board many times, the solders are all solid, I've got continuity with very low resistance between the pads on the WS board and the back of the PCB. I don't think I've cooked anything.

Does anyone have some ideas/experience with low WS board output that they can share?

(Edit: I have taken the time to read this entire post looking for ideas...).
(Edit2: I'm using a second hand J702T amplifier, and have swapped it for a new HUCO 138403 amplifier with no change, so they both seem good)
 
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Disregard the above... I have it working... turned out I either damaged my EZK (white label ...152, 16v EZK) or it doesn't like the WS board. I soldered the WS board into another EZK, more carefully, (pink label ...169, 8v EZK), and that did it. It runs.

So for the record I'm running a B230F +16v with it. Coil per cylinder. Bosch HEC715 coils, which have a similar dwell requirement to the recommended Bosch 2x2 coil recommended for the WS board.
 
Disregard the above... I have it working... turned out I either damaged my EZK (white label ...152, 16v EZK) or it doesn't like the WS board. I soldered the WS board into another EZK, more carefully, (pink label ...169, 8v EZK), and that did it. It runs.

So for the record I'm running a B230F +16v with it. Coil per cylinder. Bosch HEC715 coils, which have a similar dwell requirement to the recommended Bosch 2x2 coil recommended for the WS board.

Hey, I didn't see your earlier post, but good to hear that you've got it figured out. The 152 EZK isn't one that I have experience with - so it's possible this one may not be compatible with the Buchka Wasted Spark board.

If anyone else has experience with wasted spark on a 16V EZK, positive or negative, please feel free to chime in.
 
Hey, I didn't see your earlier post, but good to hear that you've got it figured out. The 152 EZK isn't one that I have experience with - so it's possible this one may not be compatible with the Buchka Wasted Spark board.

If anyone else has experience with wasted spark on a 16V EZK, positive or negative, please feel free to chime in.

Thanks for getting back to me Duder. I had a bit of a search. There is a green 152 and a white 152 EZK. Mine was white, no EGR, came from a Aussie 940GLE 16v. The green ones may be +EGR. I?d definitely be interested to hear if anyone else has successfully modded one.

Also some further setup feedback if anyone is interested: After a couple of drives the car is starting to run a bit rough, driveable, but not as smooth as initially. The idle is very choppy with the AFR?s bouncing around erratically so I think I?ve fouled a plug. Perhaps the Bosch HEC715 coils need a longer dwell time. I wasn?t really getting the big blue sparks that others have reported with them. I?ll inspect the plugs and report back. :roll:
 
Hi all

On the topic of gold boxes.

I have recently done my third buchka board conversion of the last 6 months but my first in a gold box.

New Bosch 2x2 as recommended and miatas igniter (does it or does it not want to have 12v feed hooked up?)

Low rpm load and on boost it starts to break up pretty quickly and the full on misses consistantly.

Starts fine. Idle isnt super smooth. New plugs, leads, coil.

Any ideas?
 
Hi all

On the topic of gold boxes.

I have recently done my third buchka board conversion of the last 6 months but my first in a gold box.

New Bosch 2x2 as recommended and miatas igniter (does it or does it not want to have 12v feed hooked up?)

Low rpm load and on boost it starts to break up pretty quickly and the full on misses consistantly.

Starts fine. Idle isnt super smooth. New plugs, leads, coil.

Any ideas?


Im no expert, but the wiring diagrams for the MX5/Miata power stage do indicate that switched 12v is to be hooked up... it may be for the 12v pass through on the unused pin, but maybe not... id hook it up to eliminate any potential fault.

Also check the ground on the power stage is solid... are you using a good plug to the power stage? ie solid connections to each pin?

I've noticed a difference in coil performance with a bad and good 12v supply to the coil, where are you getting your switched 12v from?

Lastly what voltage are you getting on your (logic level) outputs from the power stage to the Miata power stage? Perhaps the signal is a bit low, not firing the coil occasionally.
 
Im no expert, but the wiring diagrams for the MX5/Miata power stage do indicate that switched 12v is to be hooked up... it may be for the 12v pass through on the unused pin, but maybe not... id hook it up to eliminate any potential fault.

Also check the ground on the power stage is solid... are you using a good plug to the power stage? ie solid connections to each pin?

I've noticed a difference in coil performance with a bad and good 12v supply to the coil, where are you getting your switched 12v from?

Lastly what voltage are you getting on your (logic level) outputs from the power stage to the Miata power stage? Perhaps the signal is a bit low, not firing the coil occasionally.

thanks for your reply.

I'm using the Mazda plug with about 15cm of factory mazda wiring then propper krimp connectors.

The switched 12v is the former ECU 12v supply (volvo 245 former k-jet car) and it supplies the coil as well as the ECU's now. I added a 2nd wire to the coil 12v feed, nice and thick to rule that out.

I'll measure the logic outputs. About 2.5v maximum each right?

And if they are low would that be down to bad soldering internally or.. ?
 
the signal coming from the wasted spark unit to the amplifier is around:

0.33v at idle

1.15v max in upper RPM

it increases in voltage with RPM. Does this indicate a problem with the EZK? I'd hate to have bricked a gold box.

Don't mind the wiring mess, it's the old harness.

Yes pushing through this kind of missfire is painful but I have spare engines (i'd rather not) and am trying to collect as much data as possible.

I'm running a modified chip in the EZK and ECU. For a run after this one on the video I put the stock EZK chip in, basically no difference.

See video for sound of missfires and voltage on outgoing EZK signal wire. Both channels show simlar values.

https://youtu.be/SQI_jRwqB1g
 
the signal coming from the wasted spark unit to the amplifier is around:

0.33v at idle

1.15v max in upper RPM

it increases in voltage with RPM. Does this indicate a problem with the EZK? I'd hate to have bricked a gold box.

Don't mind the wiring mess, it's the old harness.

Yes pushing through this kind of missfire is painful but I have spare engines (i'd rather not) and am trying to collect as much data as possible.

I'm running a modified chip in the EZK and ECU. For a run after this one on the video I put the stock EZK chip in, basically no difference.

See video for sound of missfires and voltage on outgoing EZK signal wire. Both channels show simlar values.

https://youtu.be/SQI_jRwqB1g

Happy to try and help! Ok it sounds like you are all over it as far as the wiring goes... I'm working through a not quite 100% setup myself.

My output seems to be around 0.8 to 1.1ish volts when cranking. I can't measure the running voltage just yet, I've swapped out my 4x Bosch HEC715 coils to try the recommended 2x2 Bosch coil and I'm waiting for some lead parts to arrive to make up the spark plug leads.

I've read this whole thread and there doesn't seem to be any concrete info on what the output voltage should be, other than not above 2.5v... perhaps 0.33v at idle isn't quite enough. Also I've not tried a gold or chipped ezk, just the stock pink label -169 box. Perhaps redo the signal conditioning wire (Vr) in your ezk... it might be affecting the output adversely.

Also you didn't mention if you ended up running switched 12v to the Miata power stage... it may need it to function properly. It wouldn't hurt to do it to eliminate that as a source of your problem.

As for mine, I was hoping I could get a coil on plug setup to work (in wasted spark config) on my B230+16v but as I mentioned it wasn't running quite right... so next step is to try the recommended coil as the Dwell requirements for the HEC715 coils may not be quite right.
 
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Happy to try and help! Ok it sounds like you are all over it as far as the wiring goes... I'm working through a not quite 100% setup myself.

My output seems to be around 0.8 to 1.1ish volts when cranking. I can't measure the running voltage just yet, I've swapped out my 4x Bosch HEC715 coils to try the recommended 2x2 Bosch coil and I'm waiting for some lead parts to arrive to make up the spark plug leads.

I've read this whole thread and there doesn't seem to be any concrete info on what the output voltage should be, other than not above 2.5v... perhaps 0.33v at idle isn't quite enough. Also I've not tried a gold or chipped ezk, just the stock pink label -169 box. Perhaps redo the signal conditioning wire (Vr) in your ezk... it might be affecting the output adversely.

Also you didn't mention if you ended up running switched 12v to the Miata power stage... it may need it to function properly. It wouldn't hurt to do it to eliminate that as a source of your problem.

As for mine, I was hoping I could get a coil on plug setup to work (in wasted spark config) on my B230+16v but as I mentioned it wasn't running quite right... so next step is to try the recommended coil as the Dwell requirements for the HEC715 coils may not be quite right.

I'll re do my Vr, connection. In fact all my wires are a little thin for my liking and I might just re-do them. A car I did the conversion on a while ago and that runs a black EZK with a daughterboard (and runs smoothly) is here at the end of the week so I will be swapping them out to rule out other components of my ignition setup. What I have is:

the 2x2 coil specked, ordered by part number. Zapped me well yesterday testing each channel manually! Volvo 940 leads (the boot is spacious on the coil side, when all is confirmed to be running well I'll be adding some silicone to fill in the gap between the boot and coil. I'm running Volvo plugs, that I have yet to gap at 0.6/0.7

I added 20 liters of fresh petrol yesterday and changed the spark plug leads for a different set and it ran almost perfectly. Not so yet on LPG. I'm having a different manifold drilled and pressed for my LPG injectors and have a set of petrol injectors being cleaned as well.

I'm hoping that with the new leads in the mail, the plugs gapped correctly and clean injectors all will be well. We shall see.

From what I've read about dwell, it would stand to reason it could be an issue, but do you have the specs of you COP's for comparison? Many people are using RR coils, or Ford stuff with success. Depending on your measure of success. My head was recently reconditioned and this engine shows little signs of wear, it should run like a top as it's my daily. So a single hiccup is one too many.


I'll report back on the Gold box vs. Black box comparison.

Can anyone confirm or deny success adding a Buchka board to a Gold box? Can anyone confirm the correct output voltages from the signal wires coming of the board?

Thanks
 
Can anyone confirm or deny success adding a Buchka board to a Gold box? Can anyone confirm the correct output voltages from the signal wires coming of the board?

Lots of gold boxes have successful wasted spark installations. My own car runs a -207 gold box with no issues, and I just installed one for a TB'er into another -207. Again, no issues.

I will work on getting the output voltage characterization and post them up on my site if possible.

-Chris
 
Lots of gold boxes have successful wasted spark installations. My own car runs a -207 gold box with no issues, and I just installed one for a TB'er into another -207. Again, no issues.

I will work on getting the output voltage characterization and post them up on my site if possible.

-Chris

Cheers!
 
ezk wasted spark with subaru coil with ignitors

I recently got a subaru coil with built in ignitors. This means that you can drive it off the wasted spark board direct . But ! There is one major thing to be wary of - the coil numbering on the coil is wrong for the volvo . Best way to be sure is to measure the coil pairs with a multimeter , they should be high resistance . The coil is very difficult to find documentation on . IT has 4 pins . If you look at the coil socket on the coil,you will see a key tab on top-from right to left :ignitor1, +12v,Ground,Ignitor 2. I may be wrong on the ignitors-if it dosn't work just reverse the pins -they are logic level 5 volts not 12v !.Initially the coil did not work-it backfired badly, so i checked the coil numbers printed on coil were wrong for the volvo (perhaps subaru has different firing order ?). I looked at the post on this page for the cylinder pairs -tryed it and it worked really well,engine is super smooth and quiet- i can hear the injectors clicking.As a side note , i ran the engine for 15 minutes to heat it -the coils run very cool which means the ignitors inside are well matched to the coil . You will however need the relay mod for tacho -i"m going to use a small transformer with a load on it -its quite bad to switch a relay coil with no load -the energy has to go somewhere-usually the driver or ignitor module . Thank you to the people at turbobricks -it's really appreciated !
 
Can someone please shed light on best way to wire in launch control circuit?
Just a 3 pin rocker switch on dash and a brake pedal switch retrofitted to the clutch pedal bracket?
 
running ls1 coils

if I'm running ls coils since they don't need an igniter can i remove the power stage?

Yes you can delete the power stage and trigger the LS1 coils direct from the WS board. Just be aware you?ll loose the tacho drive in the process. I haven?t looked in detail at the relay tacho drive mod, not sure if that works with the logic level output of the WS board or not.
 
Disregard the above... I have it working... turned out I either damaged my EZK (white label ...152, 16v EZK) or it doesn't like the WS board. I soldered the WS board into another EZK, more carefully, (pink label ...169, 8v EZK), and that did it. It runs.

So for the record I'm running a B230F +16v with it. Coil per cylinder. Bosch HEC715 coils, which have a similar dwell requirement to the recommended Bosch 2x2 coil recommended for the WS board.

A bit of a update for anyone interested. I tested my ...152 EZK (16v) in another car and it’s fine. So I ordered another WS board, a better soldering iron and fitted it. It works! So no compatibility issues with 16v EZKs. I’m using it with the recommended 2x2 Bosch coil, made a nice mounting plate for the valve cover and stock length 16v 940 ignition leads and it all works perfectly. Additionally I got a new miata power stage and plug hardware, installed that and my tacho works now too.

(If I could post pics here I would!)
 
ok.

running ls2 coil packs. d581. ran fine about a week ago. pulled strong. one issue I did notice is that it doesn't actually start until the last crank. Also seemed I wasn't getting spark until the last crank(odd)

also, ran it hard last Wednesday and came back to find out cyl 2-3 had stopped firing. ohmed out my wire harness and everything checked out. going to take the board apart and see if a connection broke or something. has anyones board failed on this way?
 
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