spark plugs tell a lot about the performance of an engine. its always a good place to start to remove the spark plugs and read their condition. you can do a search on the internet to find write-ups on how to read a spark plug's condition. that could lead you to knowing very quickly if there is too much fuel or not enough. you can go from there down your path to diagnosis. also, with the plugs out, its real easy to test if you actually have spark as all you do is keep the wire on the plug and touch the threaded section of the plug to something grounded and watch as you have someone crank the car over (always a good idea to pull the fuse for the fuel pump when doing this though, if you have the plugs out of the head).

i'm no rotary guy, but thats where i'd start.
then maybe do a compression test while i have the plugs out
then maybe pull a fuel line off and get a fuel sample and check fuel flow at the same time - checks the condition of the filter and the pump at 1 time

don't rotaries consist of a rats nest of vacuum lines?