Assuming the previous owner didn't pull any hinky engine swaps, you have an M20B27 which is basically the 2.7 liter stroked version of the i motor. Stroking it kept the revs down but bumped torque up significantly over the i. But more importantly, to your question... pop the last 7 digits of the vin number from your car into this decoder. http://www.bmw-z1.com/VIN/VINdecode-e.cgi
If it IS an e, then everything I said SHOULD be correct!
btw, welcome to the board! Oh, and I used to go to the state swim team championships out there in Anacortes every year (I am from Lynnwood, but live in Atlanta GA now) back in High School... OH THOSE MANY YEARS AGO! LOL
Hope this helps ya!