yj sputtering

Newly purchased 1990 YJ 4.2 with a Weber carb. The issue(s): Everything was fine when I did the test drive before buying it. On the way home the temp gauge slowly crept up all the way to just under the red mark and stayed there. When it got hot, it started sputtering and bucking like a bronco...

Hello and thank you for letting me post here. I just put a new 2.5l long block in my 89 wrangler and it started up and ran fine. I proceeded to do the break-in process and drove it after that to a friends house. Ran great, when leaving there, it started running very bad after starting it back up...