Hey guys. I'm brand new to the forum. I just bought a 97 Olds 88, and in 3rd and 4th gear just below 2k rpms under load, the engine/car will surge. Any ideas on what could cause this?

 

I have a 93 Cutlass with a 3.4lt. I had the same issue. You can do one of two different fixes. My problem was the Idle Air Control valve. It's located on the air intake close to the engine. You can either remove the 2 screws (torx head screws) and spray it off with MAF cleaner... or you can replace it. It's an easy fix, just depends on the money you have to spend on it immediately.