From the factory, the 2.6's were carbureted using a Mikuni carburetor. It uses a complex feedback system so it will like a rat's nest of vacuum lines. Don't just start undoing them or you'll screw it all up. Note do inspect the individual hoses for leaks though as the lines do eventually fail and will need to be replaced.
Also the most common problem on these engines is a head gasket or even head failure due to the owner allowing the cooling system to get clogged up thereby allowing the engine to overheat. Be sure before you start taking it around you check the cooling system out and have it properly flushed if it's even remotely suspect... (i.e. you're not sure... then flush it!).
Other than this though you have a pretty reliable block although it may not produce enough HP if you're expecting to drive it like a more modern SUV which has far more HP than this older 4 cylinder engine. If you wan't more power though consider a turbo swap with a Mitsu 2.6 turbo found in Starions/Conquests. Not sure if they were ever sold outside of N.America since they were US built Mitsu's.
