...the accelerator? The vehicle is a 1999 Kia Sephia with a 5-speed manual transmission and 93,000K miles. About 500 miles ago (last month), I had an oil & filter change, an air filter change, and the belts replaced. Since then, I have filled the gas tank twice. The first thing I noticed that was wrong was that when I tried to accelerate up a hill in 5th (something I did regularly to 75mph), when I floored it, the engine hesitated and bucked until I backed off the accelerator. On level ground or a much lower grade, acceleration was not a problem. The other thing I noticed was over a 20% drop in fuel efficiency. I usually average 30-32 mpg, but on the two recent tanks, I'm averaging 24-25 mpg. Neither my driving habits or even destinations have changed during this time.
Any ideas out there?
Any ideas out there?