1988 Chevy 1 ton dually w/454. Wont stay idling and it wont even do 30mph. Its also surging really bad once you do get it running. It will Tach 0-2500, 0-2500, over and over. Any suggestions?? Please.

make sure all your sensors are plugged in. Especially the Mass Air Flow sensor. I had similar issues when I disconnected it and forgot to hook it back up.