89 8V kick.
you have an air like.
pinch all the hoses to the inake,
no cracks in PCV allowed.
no cranks in any vacuum line allowed.
no diaphragms allowed to leak, Dashpot, autotranny(yours is 5sp but others) includes brake booster.
IAC stuck open ,there are 2.
fast idle happens for 2 reasons.
1: air leaks to the plenum ( or some messed with the air controls (3). the butterfly , is to be never touched (throttle stop)
2: ECU is in failsafe or backup mode (limp home) do to gross error somewhere.
racings-or-highIdle