My 2002 Chevy Blazer surges when it is in overdrive. It starts fine, idles fine and runs well until I get it on the highway. Once the overdrive has kicked in the engine starts to surge. The tachometer will fluctuate as much as 400 to 500 rpm's. I have taken it to a mechanic and he worked on the fuel injectors and changed some spark plug wires but this did not address the problem. I first noticed this problem after I had filled up with gasoline from a discount fillling station. I usually use Amoco, Shell or Mobil.
Mar 11, 2009 at 8:37 AM