Thread: Timing Drift/spikes

After datalogging a few runs on the dyno the other night I had issues with the car jumping from 16 to 30+ degrees at random points starting around 6500rpm, causing the duty cycle to jump to 92%. You can see the hard dip in the graph while the AFR's spike to 10.0

It would spike then return, then spike a few hundred RPM's later.

B14
2.2L VET
Lightning Maf
ID1000 injectors
q45 TB
OBD1 dizzy
MSD digital 6 plus ignition box
OBD1 realtime ecu

Sat with a few other tuners and we could not pin point the direct problem. Nissan dizzy's are known for drift in the AEM world but I have never come across it using any of the realtime ECU's until now.

Any ideas?