+-GSX-+

I recently got a '87 CRX Si from a friend who crashed it into a pole at roughly 15mph, destroying the bumper / pushing the engine back an inch or so. It starts up instantly and drives, although it idles fairly rough and hesitates when getting on the gas hard. It also tends to chug when holding certain speeds. The exaust smells strong (although it seems to be getting better as its driven around more) and emits some black smoke; mainly when getting on the gas hard. We did find a vacuum line leading from the fuel filter to the fuel rail that appeared to be loose, so we zip-tied it and took it for a spin. It ran better at idle and during acceleration (still hesitated while holding certain speeds, just not as bad) but completely lost all power and felt like it was about to die when going wide open. We've since removed the zip-tie and are unsure what the problem could be. The dashboard is displaying the PGM-FI warning light so i'm thinking it may have somthing to do with the fuel / air supply? Anyone have any ideas?