I just replaced the ECU in my 1994 Mustang GT. I'll save the details for another time. When I started it up, after installing the new ECU and the machine would not idle down. It runs between 2000-2500 rpm, never dropping below.
After it was up to operating temp, I pulled codes, which produced 412, 411 - both codes basically say that the ECU can't adjust the idle.
So I unplugged the Mass Airflow Sensor and the rpm dropped to around 800, but the motor was not running smooth. When I plugged it back it, the rpm went back up.
So I did some research to see if I could test the MAF. It sends a near constant 2.8 volts to the ECU.
Thoughts? Should I just replace the MAF and see if that changes the situation?
After it was up to operating temp, I pulled codes, which produced 412, 411 - both codes basically say that the ECU can't adjust the idle.
So I unplugged the Mass Airflow Sensor and the rpm dropped to around 800, but the motor was not running smooth. When I plugged it back it, the rpm went back up.
So I did some research to see if I could test the MAF. It sends a near constant 2.8 volts to the ECU.
Thoughts? Should I just replace the MAF and see if that changes the situation?