Check the intake passage for blockage and make sure someone has not shoved something in the exhaust. Then I reccomend having the trouble codes pulled. Advance Auto and Auto Zone parts sotres do this for free. Come back to us with those codes an we can go from there.
If no codes come up, you should test the fuel pressure, Both the parts sotres I mentioned have fuel pressure test gauges on a loaner program and they come with adapters to fit most cars. The test port is on the fuel rail and the parts person can give you the specification.