find a way to pressurize the system, thats what i did with my car in order to find a boost leak.
for a very elemental system i found a aerosol can cap the size of my turbo inlet, drilled a hole and pulled a tire valve stem through, then used my air compressor and ran about 30 psi through it.
still couldn't find it so i modified the system so i could take off the IC off the top of the ending and still pressurize the system.
http://www.columbusracing.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=19;t=002354
let me know if you need more help, i might be able to help you out or take pics of my "improved" system for u. hope this helps.