AAN cop convertion results in sesious problems

[Dybro]

Hi every one.

Yesterday I made a 115 coil pack conversion on my UrS4.(used the schematics made by UrS4Boy) The engine fired right up and idled very nice, but only for 10 seconds and the engine stalled. I restarted the engine and then it idled very nice for 2 minutes and then it died again. Pretty strange...

I took it for a little drive on the road. It went very well the first kilometer and then I had multiple misfires (like all the coils failing for about 1 or 2 crank revolutions). I continued driving and I discovered that this sudden random multiple misfire often could be triggered by a combination of relative fast change in RPM and some boost-pressure.
But the random misfire can also occur when driving at the highway at steady RPM and no boost. Sometimes I can drive 20 kilometres with no issues at all.

My VCDS / VAG-COM says something like: “G28 crank-sensor, random unreal signal”. I tried to mount an other G28-sensor with no luck. Then I hooked up my oscilloscope to the G28 and the signal seemed to be fine – even when I had misfire!
Then I made a little coil out of some wire and connected my scope to the coil. When the coil came near the COP’s I could see that there was generated a lot of noise in the coil. There was also a lot of noise near all the connectors at the firewall where the G28 is connected.

I tried to put in the old coil packs and I couldn’t measure any noise.

So now to the questions... Did some of you have these problems with the 115-coils?? Do you have a good solution to my sensor/noise problem???

[Dybro]

Well. I'm pretty sure that I had one or more bad 115-coils and that they maybe were fake. Luckily I could return them with the modifications I had to make. Last week i bought some real 115-coils from audi-flensburg, 38€ (30-40% cheaper compared to the danish prices). And now I have no problems at all.