In 1978, Isuzu commissioned Giorgetto Giugiaro to design a new sporty car to replace the 117 Coupe (also a Giugiaro design). They delivered several T Series Geminis to the Italdesign studio in Italy and allowed Giugiaro free rein over the design. The result of this effort was the wedge-shaped three-door hatchback called the Asso di Fiori ("Ace of Clubs") prototype and show car, that was shown at the 1979 Tokyo Motor Show to rave reviews. Giugiaro referred to the design as his fifth "Copernican revolution", integrating the design innovations of many different previous designs into one, mass producible, vehicle. Within 48 hours of its unveiling at the Tokyo Motor Show, Isuzu fast tracked the vehicle into production with minimal changes to the design.
In late 1981, the first Isuzu Piazzas went on sale in Japan, available with either 120hp (89kW), 120lb·ft (163N·m) 2.0L SOHC I4 engine or a 135hp (101kW), 123lb·ft (167N·m) 2.0L DOHC I4 engine. Five-speed manual and 4-speed automatic transmissions were available, and all models were rear-wheel drive. For the 1985 model year, a 180hp (134kW), 185lb·ft (251N·m) turbocharged SOHC I4 engine was introduced, and the DOHC naturally aspirated engine was phased out in years that followed. Piazzas were available in a multitude of trim levels including Bella, XN, XJ, XE, XG, Nero, and others. There were three different suspension tuning levels, standard, Irmscher, and Lotus.
The 1981 Isuzu Piazza XE was featured in Gran Turismo 4 as one of the cars.
For the U.S. market, this vehicle was introduced as the Impulse in 1983. For the 1983 and 1984 model years, only one engine was available, the 2.0L SOHC I4 engine, rated at 90hp (67kW), 108lb·ft (146N·m). A turbocharged model was introduced in 1985, with a 2.0L SOHC I4 engine rated at 140hp (104kW) and 166lb·ft (225N·m). The 1988 model year saw several changes. Mild exterior and interior changes were made to the appearance of the vehicle (a larger rear spoiler, fixed headlights without pop up covers, etc.). The 2.0L non-turbo engine was replaced with a 2.3L SOHC I4 engine, rated at 110hp (82kW), 127ft·lbf (this engine was offered only in the U.S. market). All Impulses received a Lotus-tuned suspension beginning in the 1988 model year, which consisted of redesigned sway bars, stiffer dampers, and a change in previous spring rates.