88 D100 issues

Ok. Buddy came over. Popped the distributer cap off to have a look. Didnt look that great but not horrible. Went to put it back on and we noticed the distributer moved. It was loose. Got a new cap and rotor. Put it on. Started it set timing by ear. Set timing the proper per manual. Truck is doing better but idle to high. Now we notice the idle speed controler is not backing off at all. Even when shut off.