It starts rough in the morning until it warms and very sluggish acceleration that slowly disappears throughout the day so far. When accelerating I've notice it only last 0-30 mph. I've had the fuel pump changed Dec 2013 and fresh plug and wires April 2014 but still is sluggish, I would like to get a honest opinion before I start pouring money into it because it hard to find a reasonably price machanic who don't want my whole paycheck to diagnose the problem. Also generally keeps a half of tank, sometimes hear a buzzing sound from tail pipe similar to a boy blowing a kazoo.