I'd take the whole FI system apart, clean everything with carb cleaner, and put it back together with all-new fuel line. The clamps must be FI clamps, so if someone's put on any of the slots/worm type, replace those. No need to remove the various sensors -- those can stay as they are unless they prove troublesome.

Put new seals around the injectors.

Clean all electrical connections shiny bright and make sure they're tight.

Remove the gas tank, take it to a radiator shop, and have it boiled out. If there's any rust to speak of, they'll be able to seal it for you as well.

Get a new fuel filter.

Sounds like a pain, I agree, but it will truly pay you to do all of that for a start. D-jet is picky about dirt, and there's a good 60 psi between the pump and the regulator (and 28 psi after that), so rotting hoses are a real hazard.

Yep, 112 HP. Goes like more than it sounds.