Difficult start, dies when given gas

Start by checking for engine codes . this is the quickest way to diagnose a problem . there could be an issue with the fuel or air input regulated by the MAP or MAF sensors or oxygen sensors . If any of these are out it can affect how the vehicle runs. Check your fuel system . Start by replacing the fuel filter . If you have access to a fuel pressure tester check your pressure on the fuel rail . If the pressure is low you may have an issue with either the pressure regulator or the fuel pump. Its also a good idea to check for fuel leaks in the lines running from the tank . Hope this helps