Originally Posted by Crzymonkey

I had the exact same symptoms you are having. The problem ended up being that the injector connectors that go through the valve cover gasket had come loose. As soon as i got up to about 30-40 mph the truck would shutter. The tab that holds the connector together is a bit weak and gets weaker over time. if u cut 1/4 off of a quarter and fit it under that tab it will never come lose again and the valve cover itself holds it from ever coming out.