Theres afew wiring differences between the 2, also XR2i's ran on 1AFA not OFAC or OFAB.
The OFAC is the newer of the 2 turbo systems, but alot of people dont like it. You can adjust the idle manually also, with a small screw on the TB.
Have you check and cleaned all the breathers?
I would also clean the inlet manifold and TB with a carb/inlet cleaner.
Then put new plugs in and check the gaps, as they are very fussy about plug gaps ive found.
It would also be worth getting the injectors cleaned.
Then you have a decent base to work from and start running tests.