4.3 hesitation

my 99 silverado started hesitating. When i step on the gas, it bucks. Took it to dealer said cde showed no. 5 spark plug wire was bad. They put a used one on to get me by. No plug wires in stock. Started doing it a block away. I put new wires on, same problem. Plugs only have 3,000 miles.Coil wire replaced 2 years ago. Truck has 172,00 miles. Problem started all of a sudden.

Spark plug wire diagnosis isn’t what it used to be. Funy that nobody is suspicious of a broken engine mount yet. Try another funny trick which won’t always work. Disconnect the battery, reconnect and see if the problem goes away for a while. If it does, I would wonder about the engine computer. There are many other possibilities that used to plague older cars like the hot air tube being disconnected from the plenum chamber. Cold air getting to the throttle body and whatever other device that could stop working. Somebody has to do a little more work than changing a plug wire.

cleaned injectors and replaced roto and cap. Runs like new.