Rcently purchased a 2003 Miata Se with the 1.8L motor.. When first started it will idle fine but when you start to drive off it surges/stumbles and until you have gone roughly 1/8 of a mile is not much fun and my wife says is embarrasing..
After that 1/8 mile it runs good and you can barely feel a surge when accelerating. I mean it is probably 90-95% good.
Is this a common problem or not?

130k
bone stock
no codes

6 speed

 

Did you check the air intake hose for cracks?