Car idle issues and running lean with no codes

[Talons98]

Just purchased a 2009 mustang gt/cs two weeks ago. I’ve began my normal maintenance when I first get a car. Oil, plugs, sensors, cleaning tb. I noticed a few idle issues and the car is running lean. When ac is on the idle surges down from 730 to 600 then to 900. The car also seems to have a hard time finding idle after rebind to 3000. The freon levels go up in down in the green but never lower or higher, clutch stays on for the most part. I also have a bucking issues when the car is cold and driving in first gear. I checked for vacuum leaks and found none. I checked for freon leaks with dye and found none. I’ve also notice one maybe two injectors are very loud. They still fire normally but are much louder than the others. I used the screwdriver technique to listen and it’s not from the valve cover it’s the injectors. This I believe is causing the car to run lean as the long term fuel trim is about 15. Lastly I checked the battery and it’s old but it’s still showing 12.4v.

 

[Dino Dino Bambino]

You might want to remove the injectors and take them to a specialist that can flow test and ultrasonically clean them.

 

[Talons98]

That’s my plan on my next day off but I’m not sure if that’s causing all the issues.

 

[Edqe]

I just went through this issue myself. Here is the FIX.

1) If you have an SCT scanner go to special functions and reset KAM. Reload your tune, if your car is tuned. Otherwise ignore this step.

2) If you don’t have an SCT scanner. Unplug battery negative cable. Place a jumper wire between negative and positive cable. DO NOT touch negative battery post with that jumper wire during this step! Leave it there for 10 minutes. Reconnect negative cable.

When 1 or 2 is complete. Proceed to idle relearn steps and drive cycle.
1)Turn OFF all accessories
2)start car
3)leave on idle until cooling fan kicks ON. Let idle for another couple minutes.
4)turn on A/C. Let it idle for another couple minutes.
5)put it in drive and hold the brakes. Let it idle for a couple minutes.
6)DRIVE it around to complete drive cycle.

 

[Edqe]

Forgot to mention turn A/C off before putting it in drive.