mitsubishi v6 problem

I have a 94 mitsubishi mighty max pickup v6 4x4 and lately its been idling rough and stalls spontaneously when the idle gets too rough. On one trip to the video store it died on me 5 times. Ive changed the air filter, fuel filter, and spark plugs and none of it has really helped. My plug wires are still in decent shap so i dont thnk that would be it. Does anyone have any suggestions? I read the manual and it said that the wrong grade octane could be the culprit and/or a faulty PCV valve. Please help my poor truck, it cries and is starting to make me cry.

I think it could well be the fuel feed being to high, have a play with the carb bro, mind don't alter it too much.