Why would a 1987 Toyota truck accelerate without pressing gas pedal?

A 1987 Toyota truck may accelerate without pressing the gas pedal due to several potential issues. One common cause is a malfunctioning throttle linkage or a stuck throttle cable, which can cause the engine to receive more air and fuel than intended. Additionally, a vacuum leak or a faulty idle air control valve could lead to unintended acceleration. Lastly, issues with the fuel system, such as a malfunctioning fuel pressure regulator, could also result in the engine running too rich, causing it to accelerate on its own.