Limit IIS CPU but not ignore requests

Question

In a project we have an Java application, that make requests to an C# application allocated IIS, all is installed on a same little computer. The problem is that the usage IIS CPU is very high, when make 3 simultaneous requests the CPU is in aprox 80%, and when make 4 requests the computer is blocked.

We need that go down this CPU usage but without kill any request, if necessary, they can be slowed down.

We aren't expert in IIS.

Thank you in advance,

since this question is about configuring IIS, and not at all about programming, server fault might be a better place. — Franz Gleichmann
Is possible that the problem is related to the application, that it is a C# service working with EmguCV, the C# wrapper of OpenCV — asegurpe
possible? yes. but without knowing anything about your implementation it is impossible to say. — Franz Gleichmann