Lately the 305 TBI in my 91 RS seems sluggish ( at least more than usual, its all stock ) , low speed throttle response really sucks. It dosen't seem to matter whether the motor is hot or cold. Any thoughts on what could be causing this?

 

Take the lid off the air cleaner housing while it's running and watch how the injector spray pattern looks. If there are any drips, or just a lousy spray that's most likely the problem. Try some injector cleaner, but if that doesn't work, replace them.