[Curth]

I have a 1999 Silverado. It has 112,000 on it. Last year I got a new fuel pump, because it would not start consistently. It is a 5 speed v6 vortex.

My present problem is that when you let off the gas, the engine bucks and jumps. This is after you reach cruise speed and you wish to just maintain current speed. No codes are set. I had a mechanic look at it and he was unable to find a problem with it after he sprayed the plug wires down to looking for arcing. The truck has ran fine the remainder of today (when I took it to the garage).

Can anyone help me?