2000 Blazer Fuel Line/Injector problem

Fuel is not getting into the engine of my 2000 Blazer. We had to replace head gaskets due to coolant/water leak, as well as replace the radiator due to a small crack. There was no problem with the fuel lines prior to taking apart and putting back together, and everything was put back together properly. Fuel is making it to the lines, but not getting into the engine, so car wont start.