Voltage drop on pin 23

[Tobisen]

When I messure with the scope from pin 23 to ground with engine running, I messure spikes of voltagedrops on a few ms!
I have had the pinconnector out to solder, and the other end is also soldered and connectet directly to batteryground!
It looks like a bad wire to me, but the Microsquirt and the wirehairness is brand new!
I have made a print from the scope:


One other strage thing, when I messuer the amps with the scope for the coils, it only use 2! I have tryed to change the dwell from 3 to 4ms but still only 2 amps! 'the coils are stock 3ohms.
On a normal car, I would say the use 6amps to charge!

[Tobisen]

Maybe this is connected to this:
I can only get the engine to rew 7000rpm, then it backfires from the exhaust LOUD with 1/2 meter flames!
Is is like it looses the ignition, I can see that with the timinglight!
Is it because the coils not are charged?

[grippo]

I am guessing that you are losing synch after 7000 rpm, but the only way to be sure is to datalog the run and see if the rpm goes to 0 at any point. That would probably mean that the noise you are seeing has grown and is affecting wheel synch. Also, if you are checking the timing, does the timing measure the way you expect it all the way to 7000 rpm ? If noise spikes come in before synch is lost, that can mess up the timing and cause backfires.

[Tobisen]

I changed the wire today, and now the spikes are gone!
I have tryed to follow the timing whit the timinglamp, and it is perfect!
I have also tryed to change the advance to 30deg at idle, just to check that it was 30deg with the lamp...

The problem could be noise you say?
I have not tryed to data log, I might try that tomorrow!
If it is noise, then the rpm gauge will drop to 0?

I was also thinking, maybe it is my coils? I might have to change them to some with lower ohms than the stock 3ohms....?