Quote Originally Posted by Ardeshir View Post
I own a 1990 Cutlass Ciera with 3.1 engine. I recently decided to upgrade the engine, I had a new block with new pistons and... and set of new heads which belong to 2.8 engine.i put all new stuff on the car but now it starts pinging on hard acceleration and uphills ...! but it idles well.
The pinging is gone as i remove the Knock sensor !! but the performance is not still great.
I just checked the knock sensor with Rockauto and they used same part on 2.8 and 3.1 engines.

Should i use another ECU on 2.8 engine ?!
I just have to ask, did your 1990 Cutlass Ciera truly have a 3.1L and not a 3.3L engine? It was my understanding that the 2.8L engine was offered during years 1987 to 1989 and the 3.1L wasn't offered until 1994 for this vehicle. I ask because the tuning would be quite different between these two engines. As for Dave W. question, I believe the 1990 ECM was the 1228706.