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Hi all,
I'm hoping someone can shed some light on a problem I'm having on a friend's aircooled VW.
The ecu is an S40 which is part of a VW Speedshop kit he boought 2nd hand, it's running crank trigger, wasted spark ignition using a VAG coil pack. Having fitted the kit, it appeared that the coil was weak & although trying to start, the engine wouldn't quite fire up properly. At times almost sounded as though the ignition timing way out or the plug leads were in the wrong order (which they weren't).

The map is not perfect but I would at least expect it to run, it's from an almost identical spec' engine.

I fitted a new (pattern) coil & it fired up pretty much straight away, i shut it off to change the map, started it up again & it ran for perhaps 15 secs then died... The coil pack had fried, the casing had cracked in 2 & the resin potting had crazed...

I checked the coil on time (2500), I replaced the coil connector & wiring, remade the ground connections & fitted another new coil. In the diagnostics everything was fine, I popped those little LED lamps onto the spark plugs to watch everything work, all great. After a little cranking & farting (as though the leads are wrong) it fired up again, sounded good so I kept it running to warm up a little. This time after maybe 3 mins it backfired & died... No spark from the coil again, dead as a Dodo...

Am I doing something wrong?!? Could the ecu be putting too much current through the coil & killing it? At the moment i'm lost, I've checked all the associated wiring & it's all fine, anything that looked even vaguely suspect has been replaced. I'm now wondering why the kit was for sale in the first place, did the previous owner know there was a fault?

Sorry for such a long post but I'm losing the will with this one, any help or pointers would be very much appreciated.

Thanks
Gary

It would help if you stated exactly what coilpack you are using. Pictures, part number, something useful.

Most likely though it needs "external amps" checked on general engine settings. But again, without knowing what you're working with, impossible to say.

Sorry , it's a Bora/Golf coil pack 032905106B



Many thanks
Gary

That coil has an internal amp ( well the big alloy bit is the amp ) so you should ahve external amps checked in general engine settings

Check this or upload your map.

The 'external coil amp' is unchecked in the settings.. Does that mean it's been using 12v instead of 5v or something? I'll get another coil & try again with the new setting.

Thanks so much for your help

The on times are reversed, so you were turning the coils off for 2500us, then back on.

As above, no wiring etc needs altered.

It just means for example...if you had 10s in between cycles.

instead of charging for 2.5ms and resting for 7.5, you were charging for 7.5ms and resting for 2.5

Check the box and you should be sorted.

Just to let you know I fitted the new coil, changed settings & it fired straight up.

Thanks again