The Japanese were suck in China in a war they found out they could not win so the Japanese could not have won. If they had not been involved in China then they have a better chance.
Best chance for Japan to win a Pacific War would have been to keep Army at bay and sticking to her substantial conquests Japan had already conquered (Formosa, Korea, Manchuria). Series of decisions to invade China in 1937 were a complete disaster ultimately resulting in situation of August 1945. By playing anti-communist card and supporting the war against Germany (maybe even participating in it) would have gained Japan a tremendous economic boost.
Of course, if Japanese leadership knew all the things available now she could have waged more effective war against the West. But that's more in region of speculative fiction as CalBear said. IMHO, the best course, in hindsight, might have included following elements, many of which border on ASB.
1.) No raid on Pearl Harbor. If the US battle line decides to go charge towards Philippines the IJN is more than capable of making much more destruction. IJN was fighting the last war, 1904-1905, when the surprise attack on Port Arthur was a success and Tsushima even greater success.
2.) After conquest of Philippines and Singapore an immediate repatriation of prisoners who would have been treated well. Offer of "Finlandized" Philippines to Philippine leadership, eg. basing rights. This is utterly unfeasible for Japanese mind.
3.) No Solomons campaign. Total waste of effort.
These are for starters, but Japan either was or might have been inflicted a decisive damage in so many areas that a Japanese success is mostly infeasible. For example, in hindsight Japan could have been well defeated by sub campaign alone. Japan was already outstretched by 1941, before start of the war.