GM low efficiency

I have GM 97, 77,000 mile on it.
The problem is when I try to accelerate the car, it takes some time to speed up even if I apply more gas. in addition, the sound of the engine is much like diesel engine.

any idea about the cause of this problem?

See other recent posts, could be carbon build up inside intake, might need tuneup or other stuff. Lots of answers in previous stuff.