Hi,
I would start by looking at the following metrics in esxtop when the issue is being reported (real time)
%CSTP, %RDY
Also you can find more details about the other CPU, Memory & Disk IO statistics here Interpreting esxtop Statistics. This will help you in troubleshooting the issue. My first guess is to consider 4 vCPU requirement for this VM, if you see high %RDY time, reduce the number of vCPUs.
Hope this helps.
-f10