Chugging Eurovan


I’ve got a 93 Eurovan that lurches between accelerate and decelerate when trying to hold a constant speed. I’ve tried (paid for) everything that even the VW dealer, and two other local mechanics, can think of, including valve and top engine cleans, two new oxygen sensors, serp. and timing belts, gas treatments, and I’m sure I’m forgetting something. It runs beautifully for 200 miles and the next day it chugs after 20.

Any suggestions?