I have a K1500 1995 with 96K miles. It starts fine and runs fine until I get it warmed up and come to a stoplight. Then it "shudders" a little like it is going to die and then revs a little and goes back to normal. It might do this a couple of times while idling. I also notice a single "click" coming from somewhere around the dashboard; it sounds like it is just behind the radio area.

What I have tried so far: new plugs and wires, new fuel filter, new distributor cap. What's next? Thanks!

 

My first thought was oxygen sensor, and it still could be at fault, but the click makes me think it could have something to do with the electronic spark control. Good luck!

 

Thanks! Is there a way to test it?