Location of Throttle Position Sensor on a 01 BMW Z3 3.2L-L6

Get a OBD scanner and check for codes, considering the engine speed was high at idle and now it won't start it could be a few different things, most likely a sensor. Something like the idle air control, throttle position sensor, etc. But its going to be hard to tell which one without getting some info from the car with a reader, that is if your lucky enough that a code was set. Did the check engine light come on when it was running the previous day?

Try depressing the gas pedal slightly when cranking, not too much just a bit as it might not be sensing the throttle position, see if it will start then.

It is likely that the engine management system has lost its base line calibration. If the battery is weak and during the crank to start the voltage dipped low enough the Engine Control Module lost its calibration. If the pedal is depressed during the crank the TPS (Throttle position sensor) will lose the idle position for the throttle. The hunting and surging and resultant stalling is the ECM seeking out the limits and re-establishing the throttle idle plate location.

If battery is OK than running the car allowing the calibration of the vehicle to reestablish itself will correct the problem. My experience is that this happens if the gas pedal is depressed during crank with a very very low battery voltage. Always the best way is to not touch the pedal during any cranking starting procedure. Or after a battery replacement.

To accelerate the calibration process attempt to run the car ingear tring not to allow the car to stall. After afew munites the car will have reestablished its normal running calibration and you will be allset.

Sounds like a throttle position sensor. It is a variable resistor that moves with the, "gas" pedal. What happens is it wears out in the position it spends the most time, say 40 mph. Then it can't properly report the position of the pedal to the car's computer, it looses connection, and the computer thinks you just let off the pedal completely, and the engine goes to idle. A slight movement of the pedal goes to a less worn spot, and the fuel flow comes back to the engine.

Usually the problem of hesitation is caused by a faulty throttle position sensor or low fuel pressure, and stalling is a dirty throttle body or faulty idle air control valve.
Is the check engine light on ?

Check the help links related to this problem.Click the link below to go through its troubleshooting procedure :-----Idles rough and quits when gas pedal is pressed less? http://technoanswers.blogspot.in/2012/01/1999-ford-f-150-idles-rough-and-quits.html---------
Car won't start without hitting the gas pedal? http://schematicsdiagram.blogspot.com/2011/12/car-wont-start-without-hitting-gas.html
-------Complete loss of brake pedal then all gets normal? http://repairhelpcenter.blogspot.com/2012/01/complete-loss-of-brake-pedal-then-all.html
------Car dies when gas pedal is pressed? http://schematicsdiagram.blogspot.com/2011/12/car-dies-when-gas-pedal-is-pressed.html
--------Pushing on the gas pedal, but the car slows down? Gas pedal to the floor and the car slows down?

http://technoanswers.blogspot.in/2012/02/pushing-on-gas-pedal-but-car-slows-down.html

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After replacing brake rotors and pads, brake pedal remains on floor? http://technoanswers.blogspot.in/2012/02/after-replacing-brake-rotors-and-pads.html

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accelerator pedal sensor? http://technoanswers.blogspot.in/2012/02/2009-chevy-impala-accelerator-pedal.html

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For rough idle issues and problem troubleshooting,go through the help links provided below :----- van idles rough?

http://howtobyme.blogspot.in/2012/01/2004-ford-freestar-van-idles-rough.html

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will not idle when cold?

http://technoanswers.blogspot.in/2012/02/ford-explorer-40-will-not-idle-when.html

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runs lean and idles rough?

http://technoanswers.blogspot.in/2012/02/ford-runs-lean-and-idles-rough.html

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Engine stumbles coming off idle when warm?

http://repairhelpcenter.blogspot.com/2012/01/engine-stumbles-coming-off-idle-when.html

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Erratic idle on car?

http://schematicsdiagram.blogspot.com/2011/12/erratic-idle-on-car.html

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Low idle when cold out side?

http://repairhelpcenter.blogspot.com/2011/12/low-idle-when-cold-out-side.html

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Idle Air Control (IAC) Valve Replacing?

http://schematicsdiagram.blogspot.com/2011/12/gmc-idle-air-control-iac-valve.html

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Engine quits at idle?

http://repairhelpcenter.blogspot.com/2011/10/engine-quits-at-idle.html

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Car overheats and Air blows hot at idle?

http://howtobyme.blogspot.com/2011/11/car-overheats-and-air-blows-hot-at-idle.html

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While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

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This will help.

Thanks.

The throttle position sensor responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage and emits the voltage signal to the ECM. In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM. Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This one controls engine operation such as fuel cut, etc. The throttle position sensor unit has a built-in “wide open and closed throttle position switch,” which is not used to control the engine. For the G35, the throttle position sensor is part of the throttle control actuator.

IF YOU ARE GETTING A THROTTLE PEDAL POSITION SENSOR FAULT CODE.THE THROTTLE POSITION SENSOR IS THE WHOLE THROTTLE BODY UNIT IS THE THROTTLE POSITION SENSOR.THE SENSOR NOT IN GAS PEDAL LIKE VOLKSWAGON. VOLKSWAGON HAS THE ACCELERATOR PEDAL POSITION SENSOR.

Hello. The Throttle Position Sensor (TPS) is on the outside of the throttle body assembly. It's beside the throttle plate inside the throttle body. Once you remove the air cleaner from the throttle body you will see what I am talking about. I hope this helps, please don't hesitate to ask any other questions about this.

sound like throttle position sensor.have it check out.also check air duct connected to mass air flow sensor and throttle body.if air duct is loose or off.it will cause severe hesitation.

scan it.check the throttle position sensor.and check air duct that goes to throttle body. for leaks holes and cracks.make sure its tight.