How do you tune up a 1990 Volvo 460 turbo?

To tune up a 1990 Volvo 460 Turbo, start by changing the oil and filter to ensure optimal engine performance. Check and replace the air filter, spark plugs, and ignition wires if necessary. Inspect and adjust the fuel injection system, and consider using a quality fuel additive to clean the injectors. Finally, ensure the turbocharger is in good condition, and check hoses and connections for leaks or wear.