Release the Cancel button once the LED lights come on. This resets both the printer and the NVRAM together. Press and hold the Reset button near the back of a 5P or 6P printer as you turn on the power. Holding it for less than 20 seconds resets the printer only.
Once the throttle body is exposed, spray the throttle-body cleaner inside the air duct, and use the brushes to gently dislodge the dirt, gum and varnish that are present. Note: Be very careful not to let the thin, plastic spray nozzle (or anything else!) fall into the throttle-body opening.
A Throttle Body Injection (TBI) system has a single throttle body which contains one or two fuel injectors. The injector(s) spray fuel into the intake manifold. TBI systems were used in the late 1980s and early 1990s. In a Multipoint Fuel Injection (MPI) system, each cylinder has its own individual fuel injector. Each injector is mounted on the intake manifold and sprays fuel directly into the intake port for its cylinder.