The timeout period elapsed prior to obtaining a connection from the pool.

We recently migrated an ASP application from Windows 2008 R2 IIS 7.5 to Windows 2012 R2 IIS 8.5. The application worked perfectly on IIS 7.5, but is throwing the above error on IIS 8.5. Without changing any of the code in the application, are there any adjustments that can be made in IIS 8.5 to fix this error? 

Thanks,

John