Engine surges, check engine light is on, when I unplug a connector (maybe 12 pin) at the top of the throtle next to the idle adjustment screws the car runs fine. It even runs fine sometimes when the 12 pin plug is connected, but it eventually went back to surging. It is not surging now but the check engine light is on and I am sure it will surge again. It started fine when it was warm, but it would not start when it got colder outside. The engine ran perfect when it was warm after surging right after replacing the ECM which was diagnost as reading all absurd temperature and was reason it would not start. I am afraid the ECM got burned out of time due to something else wrong because I am back to a surging engine with a check engine light again after replacing the ECM.