Hell everyone. I am a relatively new diesel owner. I have a 93 Chevy 1 ton dually. Recently it has started a new issue, which is the lunging or surging that I have heard others talk about. It only happens when I am driving, it idles fine and does not stall out. Sometimes it happens for a few minutes, and other times it will last longer, and sometimes it will not do it at all. Since my truck is a 93 I have no pmd. I have replaced fuel filter, checked for steady fuel flow and thoroughly checked all connections. Injectors were replaced about three months ago and glow plugs a month ago, as well as the glow plugs relay. Not being an experienced diesel owner is showing. Any advice would be greatly appreciated. Thanks in advance.