Hi,
I see you have already boosted the max Java heap space for this ADP to 4 GB (-Xmx4g). Do you remember the peak memory space from your BI4.0 task manager for this ADP process when it has CPU spiking and what is the total system RAM size, e.g. 32GB? The reason is that if the java is attempting large heap space and it may be forced to use the swap disk space if the system resource is over-utilized, and swapping would definitely trigger the CPU spiking.
If your system RAM is plenty when the ADP CPU spiking occurs, the cause of the root problem is somewhere else and I'd suggest you to have a SAP BO support to enable the tracing to see when the bottleneck is and why the spiking
Regards,
Jin-Chong