I have a 2001 WG Grand Cherokee V8 and suddenly it now runs rough at idle and under acceleration. The amber engine warning light has suddenly come on as well. Thought it might be a fuel problem.
Many auto parts stores, including AutoZone, will check engine trouble codes. (You can also do this yourself if you have an OBD-II code reader.) If there is a "check engine" light on the dashboard, chances are that one or more codes will show up and point you in the direction of the problem.