I think the 92 is EFI, and there is a sort of IAC but it's a throttle
kicker, pushes on the flat tab on the throttle linkage, and is close
to where the throttle cable attaches, if there is a problem with
the vacuum actuator controls it could be pushing the throttle open
and then backing off, if that doesn't help, then it could be the wax
pellet that is the cold air start control, I never messed with mine
but there is a fix that uses a piece of rubber hose to block the passage
that allows the air into the engine under the throttle plate
Wild