EVO Board not firing coils

[grant620]

Hi,
A customer of ours has a GEMS board on his Rally EVO 6.
Recently we sold him one of our plug and play coil on plug (COP) kits, which plugs into stock wiring. This means that it fires 2 coils at a time in a wasted spark configuration, just like stock.
The GEMS ECU will not fire the coils at all though. We have had the kit back to test and it works on stock ECU, LINK, Autronic, ViPec and Hydra... But won't do anything on GEMS.
Any ideas why?

Thanks in advance.

Grant

[RickS]

Just a thought... The ignition coil charge time is calculated from the battery voltage and the engine speed. Different coils will probably require different charge times. In the EVO 6 ECU parameters, Coil_Factor adjusts Charge_time that in turn controls the level of charge held in the coil. The higher the value the greater the charge. It is important that is neither too low (weak/no spark) or too high, which will result in overheated coils and amplfier. If your customer is getting either weak or no spark, this could be the reason.

HTH

[PQatPIT]

... it works on stock ECU, LINK, Autronic, ViPec and Hydra... But won't do anything on GEMS.

Might be that Gems ecu doesn't pull high enough the ignition signal. This could be checked with oscilloscope to really see what is going on. I bumped into this with some other brand ecu just recently, and it was fixed with stronger (lower resistance) pull-up resistors in ignition output line.

Usually the limits are about three volts to activate coil charging, and one volt to give out spark. Coil amplifier/module internal pull-down resistor is usually something like 300 to 800 ohms, and ecu signal output stage must be able to pull up signal voltage against that.

Of course might be something much more simpler, ie. wrong pin connection and such

[RickS]

I would like to get my hands on some technical data regarding these COPs. Unfortunately, the manufacturer will not release this information as 'the operational aspects are proprietary to the OEM'. We will have to test this installation on the bench to ascertain why there is no spark.
HTH

[grant620]

The coils and board will be with you next week.

[RickS]

For others reading this post, who may be having a similar problem, an EVO 4 ECU will not fire these particular coils without a hardware change to the ECU.

Happy calibrating!