1992 Isuzu P'up

My 2.3 ltr engine is revving high and it just recently started doing this. I tried adjusting the throttle rest adjustment screw but it did nothing for
it. I should note that the carburetor has had a moderate miss to it for some time now. I took the filter element and housing off and it still revs high. I checked for proper connections of all vaccum lines. I have an aftermarket air conditioner that was installed in 2000. The engine has 111,000 miles on it and does not smoke.
Can anyone offer some advice.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.