Ok guys, I really need help with this one. I did a VR6 swap in my '91 GTI using the motor, harness, and ECM from a '95 Passat GLX. When the swap was finished the motor would not start; it turned over but didn't start. I ordered another ECM with the same last numbers 258BS and it still would not start. So I borrowed my friends ECM from a swap he had performed using the motor from a '96 Passat GLX ending numbers 259L and the car started. My car is an OBD 1 and my friend's car is an OBD 2. Can someone please explain to me how an OBD 1 motor can work with an OBD 2 ECM but not with an OBD 1 ECM? According to VW the computer that should run my car is the 258BS and not the 259L. I cannot continue to use the OBD2 computer because the car is running very rich and has a very rough idle. Also when I disconnect the plug from the TPS the car idles fine and does not smoke. I have replaced the complete fuel rail, O2 sensor, MAFS, and TPS. Please respond . Thank you in advance.