Hey guys I recently bought a 1988 Mitsubishi Mighty Max for pretty cheap, I just needed to smog it. Sadly, it was labeled as a gross polluter so now I have to go through the referee (California). During my first appointment he told me that the truck had an engine swap (he was guessing a 1991 was put in) and that I needed to time the truck and lower the idle speed before I brought it back. The idle speed just won't come down.

The idle screw is backed completely out, not even touching at this point.
The accelerator cable has slack in it, and won't turn any farther back. When you apply pressure to the accelerator plate/pulley thing backwards the idle does drop, however it hits a plunger that won't allow it to turn back farther?

Does anyone know what this plunger thing is, or how to adjust it or the idle speed? Sorry I don't know all of the proper terms to describe the problem.