i am frustrated with problem and no one so far has answer . have 99 silverado 2500 with 6.0 and 184,000 miles on it and at idle the motor will surge and some times on acceleration. no light ever comes on . had in many shops with no problem found . can anyboy help me thanks mike

So you've checked for vacuum leaks? Can you create any of the conditions to make the idle surge? Other than the surge does the engine have any other problems, even ocasionally?