DDK - Die Deutschen Klassiker

That's interesting Shirish - sounds like a not uncommon fault which makes me feel better about it

Definitely worth checking the reset counts for power losses and also the counter for crank sensor drop outs.

If there was a critical power fault I have thought the log would be missing (it saves the log after every sample period, if using the SD card). I wonder if the ECU cuts the overall power (to injectors, sensors, coil packs etc) if the crank position is lost as plugs firing at the wrong point can do nasty things. The reset counter should settle that question.

As always, you need a perfect ground and power connection.

OK I've emailed David at Canems now and sent him my logs

this morning on the way into work I set up monitoring and looked at the power out stuff

I took it beyond the 6200 cut-out

CPU information:-
Power on resets, External resets, Brown out resets, watchdog resets, JTAG resets - all at zero before and after the cut-out

Crank Sensor information:-

while normal driving Sensor rejections, TDC window and Ref. Sensor all at zero
When I triggered the cut-out it went to :-
Sensor rejections:- 80
TDC window:- 3
Ref. Sensor:- 66

it remained there fore the rest of the journey and didn't change again (I didn't trip the cut-out again)

Does it trip statically at the same rpm? I appreciate this will be a noisy test...

I've not felt like trying that - if I did I'd want to do it on the lower limit (i.e. without the resistor in) - and at the week-end....

Well that looks clear enough that the crank sensor is at the root of things. Look up crank sensor diagnostics. It also talks about sensors deteriorating. I'm sure if there are some standard "fixes" then Canems should be able to help. It suggests that if faults occur here, it's probably the speed sensor fault.

Had a response from David at Canems today

"Sorry to hear you are having difficulties. The Carrera twin crank sensor setups are one of the most
difficult systems to get running and synchronised - when everything is in absolutely perfect condition the crank sensors will work OK with our unit. One of the biggest issues we find are poor earthing on the chassis on the older cars - and this could be anywhere on the car....

It can be a pain to track down exactly what is causing the issue however, and we now have a much improved pickup circuitry that we can fit to your unit if you'd like us to take a look. The modification costs £50 plus VAT but I am 99% certain that this will resolve the issue for good - if not I will refund the cost of the modification. If you'd like me to take a look just let me know."

Bear in mind this is on second hand kit that he originally sold a few years ago, I'm knocked out by the customer service. Going to go for this and currently sorting out when and how to do it.

What an excellent response - kudos to the man !

Hmm, interesting. Do you think you could simplify the triggers ? Put a 60 tooth wheel on the pulley rather than the 129 tooth ? Only if you can't find the real problem of course.

Yep if you look back a page or so that's what Shirish (corner shop) had to do for his Motec setup (using clewitts pulley wheel adapter)

Space is tighter on mine as I've got the DIS coil pack where the dizzy was, but if it came down to it I'm sure I could rig something up though.

Still, hopefully not needed

It's a long time since I studied electronics, however, a couple of thoughts.

You could run a temporary earth cable from the battery direct to the ECU & see if this helps. Also clean every earth connection involved.
Ideally the power / grounds (except the trigger) of the coil pack should avoid the ECU. I guess the benefit of this ECU is the plug-n-play so it could be a pain to rewire.
Get crazy with ferrite clamps. Near the alternator, on the crank trigger wire, ECU power / ground cables. I'm not certain they will do the job but they are pretty cheap. Maybe the DDK experts can say whether these are snake-oil or worth trying.

If not sure why the in series resister helps. Perhaps it forms a low pass RC filter with the cables inherent capacitance? If that is the case, up to 30k ohms might work (guessing the cable capacitance). I'm also wondering if a shunt resister would help. It depends on the design of the ECU input circuit, I guess.

You could add a small "conditioning circuit" or consider changing to a hall sensor.

a friend of mine has a cool trigger set-up on his vw camper van thing - he purchased it from a guy in Australia I think and it fits very neatly behind everything.. he does triggers for all sorts of air cooled engines and may have something suitable for your engine - if you want me to get the web-address drop me a PM and I can speak to dean and get the details..
He's found it 100% bolt on/bolt off and completely reliable so far (been installed about 12mo)

Thanks for all the suggestions. If Canem's solution doesn't work then I'll be considering these options

Just spoken to David at Canems and he's sending me a brand new unit over to swap out for the existing one which I then return to him

Just bear in mind I've bought my unit second hand - I'm the third owner, and Canems are replacing that with a new one with the extra fix in place. And if the replacement doesn't work they are doing this at no charge.

David has consistently been a really nice guy and provided fantastic customer service so far. Fingers crossed it does the trick!

Wow , that's some service!

There are better ICs available for sensor inputs these days so perhaps it will have some improvements in that area.

Ok, this page is boring and needs more pics of shiny bits