Chevrolet Repair: chevy silverado 1500 350 v8 1990, air fuel mixture, chevy silverado

Question
the truck will hesitate on exceleration, kind of a pulsating hestation. Drives fine at constant speed. Idles fine. Service engine light comes on and off, seems more frequent when the tank is full. I changed the fuel filter and did a tune up.

Answer
Hey,

  Have you checked or replaced the ignition wires and cap?  If you have replaced all of the ignition components you may have a missfire from a densified air fuel mixture.  Find the EGR valve.  Its located on teh passengers side of the intake and unplug the vacuum line to it. These valves on this year are bad from over retracting and giving it too much EGR.

WAyne