1990 Pontiac Firebird Fuel Injectors

My firbird has been stored for about 4 years. In a garage. I would start it now and then. I unhook the fuel filter to see if the fuel pump was still working and it was. So I replaced the fuel filter. When the fule filter was unhooked I blew out the line from the motor to the filter to make sure it was not clogged. I am getting plenty of fuel to the motor. When I turn the car over the injectors are not sprying the way they should be so I took them out and tried to clean them. When I put them in and dump some gas into the throttle body the cars runs from the gas I dumped in. When the car is burning the gas I dumped in, the injectors are just dripping gas and not spraying. I am thinking about new injectors but don't want to spend money on someting I don't need. Is there any way to test the injectors to see if they are bad or if there is another problem. Thanks