In November 1979 Ferrari replaced the 400 Automatic with the 400 Automatic i, "i" suffix in the model name standing for "injection", as a fuel injection system replaced the two banks of three side draught Weber carburettors. The car stayed into production until 1985, during which time 883 examples were constructed, in right or left hand drive steering.
The adoption of fuel injection was to satisfy ever more stringent worldwide emission legislation, and it dropped the claimed power output to 310bhp. The engine was a V12 unit with a bore and stroke of 81mm x 78mm giving a total capacity of 4823cc, with factory type reference number F 101 D 070, coupled to a Borg Warner 3 speed automatic gearbox. This transmitted power through a propeller shaft to a limited slip differential, and from there via half shafts to the independently suspended rear wheels with hydraulic self levelling units.
The engine delivered 310 hp and sprinted the car to a top speed of 149 mph.
The 400 Automatic i was initially visually identical to its predecessor both internally and externally apart from the addition of an "i" to the tail badge.
In late 1982 some mechanical and cosmetic changes took place to the model. The engine received revised profile camshafts and new exhaust manifolds, which upped the power output by about 5 bhp, and the hydraulic self levelling rear suspension changed to a gas filled system, coupled to new metric rim wheels with lower profile tyres. Internally there were revisions to the upholstery stitching pattern, door panel design, and centre console layout.
Outside the door mirrors became more elegant with small enamel Ferrari shields on their casings, the width of the radiator grille was reduced to expose the driving lights, which became rectangular instead of square, the radiator exhaust air louvre in the bonnet became body color, and high intensity fog lights were set into the rear bumper.