franklin2
Well-Known Member
- Joined
- Dec 24, 2019
- Messages
- 3,751
- Reaction score
- 1,907
- Location
- Virginia
- Vehicle Year
- 1984
- Make / Model
- Bronco II
- Transmission
- Manual
I would not turn the idle stop screw without first marking where it is, and then doing the unplug the IAC test and see if the engine is barely idling. The problem with just turning it without unplugging the IAC, the computer is going to be in the picture trying to adjust the idle while you are turning the screw, and you can get this screw open too far, and that messes up your throttle position sensor.
The computer has 3 different modes of operation, and they are determined by the throttle position sensor. It has a idle mode, above idle running mode, and a wide open throttle mode. The problem comes with the idle mode. It is when the throttle position sensor is around 1v or less. It's very easy to turn the screw too far, and at rest the TPS is above 1v and this confuses the computer and it will not run correctly.
The computer has 3 different modes of operation, and they are determined by the throttle position sensor. It has a idle mode, above idle running mode, and a wide open throttle mode. The problem comes with the idle mode. It is when the throttle position sensor is around 1v or less. It's very easy to turn the screw too far, and at rest the TPS is above 1v and this confuses the computer and it will not run correctly.