Sorry for the title, english is not my native language, so its kinda difficult to explain.

I just bought an Eclipse, 2.0 16V non-turbo, and it runs very well, except when i lift the throttle, the engine "jumps", like it misfires or something, even though it shouldn´t be possible when decelerating. It does the same when on a straight road, and the road bends down a bit. If i keep the throttle in the same spot, and the car begins to push the engine, it becomes worse. Its kinda like when there is moisture in the ignition leads. But the engine pulls very well all the way to 7000rpm, and no problem taking off either.

Any ideas? Also if it doesn´t make sense, please let me know and ill try to explain

Thanks!

Edit: When running idle, it usually hangs around 1000-1500rpm, and it sounds like it misfires from the exhaust.

 

a tune up.
compression check, new spark plugs and leads, ignition timing, fuel delivery calibration.