You should check the fuel pressure first. Most Advance Auto and Auto Zone parts stores have fuel pressure test gauges on a loaner program with a deposit.
There is a test port on the fuel rail and the test gauge will come with adapters.
I am including the fuel pressure specifications as well as injector resitance specs as they could be at fault as well. You may also wnat to run a can or two of a high quality fuel system cleaner such as BG44K or Sea Foam. You can find them at local auto parts stores.
Nov 14, 2011 at 12:25 AM