When my car is warmed up and turn ignition on, it will turn off slowly with weak idle. But when my car is cold and turn it on, it won't turn off. if I give it a gas a little before it turns off, it stays on.. What's wrong with my car.. This happened after I got my transmission fixed.

 

bump bump bump!!!!!!!!!

 

check if you have no vacuum leaks, simply disconnect battery and reconnect it. Also try simply reset ECU.

 

there are no vacuum lines near the tranny. I say if you havent bumped up your idle. do so, idling at like 680rpms is retarded. take it to the dealer, and have them set it at 850

 

^ but OP's trouble sounds like vacuum leaks or ECU set.

 

I'll give it a try. I'll reset ECU by disconnecting battery.

 

Before disconnect battery, try this first. Pretty simple but it has to be in perfect time tho.

Accelerator Pedal Release Position Learning

Operation Procedure
1. Make sure that the accelerator pedal is fully released.
2. Turn ignition switch “ON” and wait at least 2 seconds.
3. Turn ignition switch “OFF” wait at least 10 seconds.
4. Turn ignition switch “ON” and wait at least 2 seconds.
5. Turn ignition switch “OFF” wait at least 10 seconds.


Throttle Valve Closed Position Learning

Operation Procedures
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch is “ON”.
3. Turn ignition switch is “OFF” wait at least 10 seconds.
Make sure that the throttle valve moves during above 10 seconds by confirming the operating sound.


Idle Air Volume Learning (Throttle Position Learning)
It is better to count the time accurately with a clock.

Operation Procedures
1. Perform “Accelerator Pedal Released Position Learning”.
2. Perform “Throttle Valve Closed Position Learning”.
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Conform that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
6. Repeat the following (steps 7a, 7b) procedures quickly five times within 5 seconds.
7a. Fully depress the accelerator pedal (HARD)
7b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the Check Engine Light (CEL) stops blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the CEL is ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure the idle speed and ignition timing are within the specifications