I have a 2004 hyundai XG350L it has a throttle lage of 3.85 seconds and I have replaced the throttle Position Sensor to no avale. Often after turning the car off it will not start again for about 10 minutes. Can anyone help please?

Question edited for clarity.

In the link, for a paper version of to download.

https://www.google.com/search?q=2004+hyundai+xg350l+repair+manual

..

https://www.autozone.com/electrical-and-lighting/power-steering-pressure-switch/hyundai/xg350

Its located on the left side of the engine, (passenger side). Take the timing chain cover off, look for a wire just in front of two pullies, closest to you. One maybe two bolts, its probably caked with metal debri, being that it's a magnet which reads gaps in a thin disk. This gap tells the engine when to fire whatever cylinder. My sensor went bad after 3 days from purchasing the vehicle from a dealership, they wouldn't help me since there was no warranty. Pos. The engine shook so hard I thought it was going to break a motor mount, after a day it was underivable. Contact me for a diagram if needed. Hyundai xg350L 2004 3.5L repair shop manual. [email protected]

Throttle position sensor could be the problem
Emmission control parts
You mentioned idler cable
Well there may be a second idler control cable
Some vehicles come with a double cable adjustment
The second adjustment is right above the gas pedal
Turning screw
Alternator giving out not producing charge needed
But overall if your cars idle bogs down the likely culprit is your ac bout to go out
The bearings in compressor wear out so it pulls more on the engine
In turn bringing rpm's down
Your car needs routine maintenance
Ac is an expensive repair so i suggest bypass belt till you can pay to have it fixed

obviously the mechanic fixed the symptom and not the problem. Run the fault codes to check for something more serious . Contact the dealer service centre to see if there is a bulletin on this problem.

Code 121 is for a problem with the circuit for the sensor.
The computer is getting a signal that is out of range, too low or too high.
If you know for a fact the sensor is ok, you may have to check the circuit back to the computer. You would also need a scanner to read the sensor signal.

could have faulty throttle valve control motor or throttle valve position sensor.

Crank Position Sensor ? I guess you don't know what that is !

You already answered your own question,when you pulled
on the gas pedal

You can not adjust rpm's, it is controlled by the engine computer. if you idle is not right, either your throttle position sensor is not right, or your idle air control is malfunctioning, although there can be numerous other causes for erratic idle (vacuum leaks, throttle body or air filter needs servicing, etc.).

You might try testing the tps. It may have a dead spot at the high end of the throttle opening. Make sure the resistance continues to change as you open the throttle all the way.

Throttle Position Sensor

Operation The throttle position sensor is a rotating type variable resistor that rotates with the throttle body-s throttle shaft to sense the throttle valve angle. As the throttle shaft rotates, the throttle angle of the sensor changes and the ECM/PCM detects the throttle valve opening based on the TPS output voltage.
Removal & Installation

1. Disconnect the negative battery cable.
2. Disconnect the sensor connector.
3. Remove the sensor retaining screws. Remove the sensor from its mounting.

To install:

1. Installation is the reverse of the removal procedure.

Testing 2.4L Engine

1. Disconnect the sensor connector.
2. Measure the resistance between terminal 1 (sensor ground) and terminal 2 (sensor power).
3. Specification should be 3.5-6.5 kohm.
4. Connect and analog ohmmeter between terminal 1 (sensor ground) and terminal 3 (sensor output).
5. Operate the throttle valve slowly from the idle position to the full open position, and check that the resistance changes smoothly in proportion with the throttle valve opening angle.
6. If the resistance is out of specification, or fails to change smoothly, replace the sensor.

2.7L Engine

1. Disconnect the sensor connector.
2. Measure the resistance between terminal 2 (sensor ground) and terminal 1 (sensor power).
3. Specification should be 3.5-6.5 kohm.
4. Connect and analog ohmmeter between terminal 2 (sensor ground) and terminal 3 (sensor output).
5. Operate the throttle valve slowly from the idle position to the full open position, and check that the resistance changes smoothly in proportion with the throttle valve opening angle.
6. If the resistance is out of specification, or fails to change smoothly, replace the sensor.

1. Disconnect the sensor connector.
2. Measure the resistance between terminal 2 (sensor ground) and terminal 1 (sensor power).
3. Specification should be 1.6-2.4 kohm.
4. Connect and analog ohmmeter between terminal 2 (sensor ground) and terminal 3 (sensor output).
5. Operate the throttle valve slowly from the idle position to the full open position, and check that the resistance changes smoothly in proportion with the throttle valve opening angle.
6. If the resistance is out of specification, or fails to change smoothly, replace the sensor.

3.5L Engine

1. Disconnect the sensor connector.
2. Measure the resistance between terminal 3 (sensor ground) and terminal 1 (sensor power).
3. Specification should be 3.5-6.5 kohm.
4. Connect and analog ohmmeter between terminal 3 (sensor ground) and terminal 2 (sensor output).
5. Operate the throttle valve slowly from the idle position to the full open position, and check that the resistance changes smoothly in proportion with the throttle valve opening angle.
6. If the resistance is out of specification, or fails to change smoothly, replace the sensor.