m20 idles like a SBv8

[smonkbmw]

i have a 89 325ix that i swapped in a lower mileage m20 from another ix. car starts and runs fine, goes down the road fine. no overheating or anything. but at idle it runs like its got a cammed out 350 chevy v8. the car twists to one side as it turns over. almost like it has a missing cylinder or something, i dont know how else to describe it. yes it sounds weird but im not sure what to do. all the searching on here says "icv icv" but that is in earlier cars. ive changed out the icv with another and it still runs weird. ive been told to swap AFM's and thats what im gonna do this weekend. any other suggestions?

[Charlie]

i have a 89 325ix that i swapped in a lower mileage m20 from another ix. car starts and runs fine, goes down the road fine. no overheating or anything. but at idle it runs like its got a cammed out 350 chevy v8. the car twists to one side as it turns over. almost like it has a missing cylinder or something, i dont know how else to describe it. yes it sounds weird but im not sure what to do. all the searching on here says "icv icv" but that is in earlier cars. ive changed out the icv with another and it still runs weird. ive been told to swap AFM's and thats what im gonna do this weekend. any other suggestions?

Vacuum leak, check all of your hoses. I've noticed the hose to the brake booster likes to come out or off slightly on m20s a lot.

-Charlie