I have a 1997 jimmy I had a friend do my tune up and now it has a very rough idle but still runs. When I stop at a light it feels like it want to cut off but don't. He said one of the screw heads on the rotor broke so its being held down with one screw. Can this be the cause of the rough idle? The cap is tight though. Because of what he did I was considering replacing the whole distributor with a new one that comes complete with cap and rotor already installed on it. What do you guys think? Any info will be highly appreciated

 

On the rotor or the cap?

If it's the rotor, DEFINITELY and that used to happen all the time on SBC's Surely you can find way of working that screw out.
If it's a cap screw broke in the base.. ah, well.
You really dont want the hassle of replacing that dist if you can get around it. Might as well take it to a shop if you want it to run right afterward.

 

What plugs did you run? Few s10's ive seen tried them bosch +4's etc and these trucks hate em! Ngk or ac delco all the way! Also make sure you didnt cross a plug wire with the wrong cylinder etc.

 

From what I remember it was a rotor screw that broke. So try to change the cap and rotor again to see if the problem stop? Also I used Bosch plugs, so I'm going to switch them out for AC Delco's too!