2009 A6 stalling

You have a vac om leak or the idle valve stake ,all the best.

POSTED 2 TIME, BUT THIS ONE LONGER. read other post answer now.?
your engines stalls! if engine stalls so does car.
BUT DOES IT RESTART EASY,??????
Does the restart, starter sound fast and normal or weak
can you prevent the stall with fast right foot action?
ever get a tuneup in last decade?

most stalls are caused by 50 things.
top of list is MISFIRING.

http://jeepdied.com/Misfire101.html

can i buy a comma., says Vanna White>?
one rule of dealers, (avoid them use independent ASE shops)
or go broke. ($25 spark plugs there... i warned yah)
rule 2,
never take a car to any dealer unless you can DEMONSTRATE the failure. most shops can NOT fix cars that work,
they will try, and charge you CASH for trying, and no blush.

my impression is, the cars issues are INTERMITTENT.
if you dont know cars and electrics, then it may be impossible for you.
but some nicer independant shops might drive it for a day for you
to get it to fail. that WORKS, see WHY?

your engine stalls. that is the key word, random STALLS.
now lets work that IDEA.
there are 3 paths (one of them works out to 50 causes)
here they are..
1 bad DC power, 2 bad engine , or 3 vbad ISC controls.
all my answers ASSUME the car is 100% tunedup using the 60k miles column ! or up to 100k on some. cars. did you?
when it stalls can YOUR right foot (fast moving) save the stall.
??????????????????
does the stalled engine easily restart?????????????????????

The engine brain, PCM/ECU does all it can to stop stalls.
it does, if it stalls, its a very serious failure !
Now the full list ,( expanded)
1: lost of 12vdc electrical power to the EFI system. (voltmeter 101)
use a voltmeter to catch it. seen even at the cig lighter port.!!!!
2: lost spark? wont restart? (do the classic spark test)
3: lost fueling ? more tests (no start, try test fuel)
3A; flooding,? spark tips soaking wet. use WIDE open throttle to start engine and cut fuel , cranking, this help , try starting with 10% throttle ti see if ISC is stuck closed.
4: bad engine, the 50 ways and engine can fail. lost compression , on any or all cylinders , will do that. hot or cold or both .???????
one way to solve problems is by elimination.
say some head valves stick, only hot and only randomly. (nasty issues)

you find that (not saying it is, i never guess)
you prove that this way, examples
good 12vdc, power, checked.
good spark, checked. on all cylinders, not just 1.
injectors test pass, no leak down test failures and the injector balance test passes. (the FSM covers these 6 tests for fuel pressure)
conclusion"
so must be engine bad, it stalls, and runs bad , restarted or not at all.
so you find compression on 2 cylinders are low , 25psi, hot.
all else was tested good so i attack the engine'.
on old engines, i do that first.

so do tell what engine does and does not fully,
your post leaves out most facts.
stalls, and can you save the stall.
and does it restart.
and do you have 12VDC power at stall.

Probably a Cranckshaft or Camshaft sensor going bad when hot.

I haven't seen this particular isues in the Avengers yet myself, but if the ECT light is on with the engine light right before it stalls, I don't know of any other sensors that both Moduals read that could cause that.

To diagnose you will have to recreate the problem and then test the sensors to see what one is failing.

Provided the codes in both computers point you to one of those sensors.

Service Engine Soon came back on and the car is again stalling ????? Did you have it checked for DTC'S - diagnostic trouble code's ? Service engine soon light on , codes will be present !

It could be many things.
When the engine crank but won't start
Retrieve PCM faulty code if any.
Engine need 3 things (Fuel, Air, Fire (spark)
1- Fuel = fuel pump working during the problem you can hear a sound at the fuel tank cap (remove)
All Fuel Injectors working.(Power and the spray).
2- Air = MAF defect (Mass Air Flow) no code will be set
When the engine is running with a screwdriver lightly hit the MAF the engine will stall if it's the problem.
air filter restrictions
3- Fire= Is there spark at all spark plugs wire?

Find out the ground of power windows it could be the same as fuel pump or ignition system (Ground corrosion, high resistor)
and many more.
See good technicians to fix your car..

Hope it helps

In the inside of the distributor there's a sensor called the Hall Effect sensor. This particular sensor will definitely cause your engine to stall for no apparenty reason especially at low rpm. Is your timing belt due to be replaced? If the timing belt is getting worn, it can stretch to the point of retarding the camshaft to the point of it stalling as well. You'll see a drop in your fuel economy as well and it won't be real spunky anymore.

It could be the coil is getting old. They begin to lose function when they warm up.

There are usually three things that cause this problem. Either 1. your car is intermittenly having the power supply to the ignition interrupted, i.e., loose battery cable or ground, or ignition module, etc 2. your alternator is failing intermittenly, or 3. Your fuel pump is going out. The most common is the fuel pump, especially with your symptoms. The way you test, is, when it won't start, shoot a little fuel into the throttle body, and see if it hits and dies, or hits and keeps going, etc. These things are notoriously intermittent, and of course, you can only troubleshoot something when it's currently not working. As for the alternator, you'll usually have some other warning sign, such as a battery light, or failure of instruments, etc. As for the ignition module, it's more of a remote chance that I included as an option. Hope this helps you out.

You need to clean the throttle body and idle air bypass valve with spray carb cleaner, hold the idle high while you do this as the engine will try to stall, disconnect battery when done for 5 minutes then reconnect and drive a few days to relearn idle strategy.