Volvo LH2.4 EZK Wasted Spark Conversion Board by Buchka Engineering
Designed & Manufactured in Sweden / ships from USA
Created by Buchka Engineering, this board converts the Bosch LH2.4 / EZK system to wasted spark configuration. Used on Volvo 240, 740, and 940 vehicles. Installation required. Please see installation guide provided here.
This little circuit board, when mounted inside your LH2.4 EZK box (meaning in most 240s, 740s, and 940s), will let you ditch the distributor entirely and run wasted spark coil-on-plug. This means better mileage, more stable ignition timing, stronger spark, and most importantly, no more cap and rotor replacements.
Users have reported fuel economy improvements between 10% and 30% vs. the standard ignition system. Your mileage may vary.
Along with the board itself, you will need to supply coils and ignitors. Almost any coil driver will work, as long as it is triggered using a +5v signal. Most of the prototype boards have been running in conjunction with a Bosch 2x2 wasted spark coil but since dwell can be tuned you should be able to run almost any coil setup.
The boards feature all surface mounted components and the onboard software can be upgraded at any time using the built-in programming header. Please note that this is not a plug and play affair. Along with wiring and mounting the new coil(s), you will also need to open your EZK box and solder wires to various points.
**Note: On the current batch of boards, the 1-4 wire needs to be swapped with the 2-3 wire, to obtain the correct firing order through the coil pack. This happened during board programming and unfortunately we cannot change this. You may need to swap your wire leads if the engine does not immediately fire after installing the wasted spark board with the power stage and coil(s) of your choice.**
Also included in the production run of these boards is a highly experimental launch control + shift cut feature. Two extra pads on the board can be wired to momentary switches. Pushing the Set button will store the engine's current RPM in memory. The Arm switch (preferably clutch mounted) will activate a hard-cut rev limit at the stored RPM. Releasing the clutch disengages the rev limit. Once you wish to upshift, depressing the clutch will again engage the rev limit, cutting spark and unloading the driveline, allowing for a full throttle shift. The 940 Turbo this has been tested on was able to build about 6psi at 3000rpm in neutral.