Here's the problem. When the engine is cold starter spins fast. When the engine is warm starter does not have the power to turn off the engine. What could be the problem? Akku is new:-)

That sounds like a classic heat soaked starter. Either rebuilding or replacing it should fix the problem...but first check the connections and ensure they're clean and tight. That can trick one into unnecessarily replacing a starter every once in a while.

Saw this either here or the VCCA forum.  You may need to heat shield the starter.  I noted with interest as my 1953 Chevy Wagon had this problem.  If I had know how easy it would be to fix it, I would still be driving that thing. Alas, that was over 40 years ago.  See how hot the starter gets, should give you a clue which direction to go.  Never hurts to clean the wire terminals on the starter and the battery.

Best of luck!

Especially if you have headers on the car. They will heat up the starter and cause it to start like drained battery.

Another thing it could be is too much ignition advance, or bad fuel. Next time you try to start it and it seems to drag, try pumping the accelerator pedal 4-5 times quickly, then cranking it. If it drags for a second, then spins quickly and starts, you have too much advance on the timing, or your fuel is not a high enough octane for the timing. You might want to back the timing off a few degrees....you might also want to determine how much ignition advance you have to start with.
Is this a problem that just began, or have you had this issue for a while?
Has there been any work done to the engine recently(tune up, carb, etc)?
The starter solenoid getting too hot is a big issue on these cars, since everything is packaged so tightly. There should be a factory heat shield around the solenoid anyway. If yours does not have one, you really need to get one, of use one of the aftermarket shields.

Adam I have a problem with the ignition as well. But here is not about a problem with the firing but with the rotation starter. I think the starter should always rotation the same. I have a heat shield.

|UPDATED|4/8/2013 4:42:08 AM (AZT)|/UPDATED|

The starter being too tight against the flywheel could do that, but...it wouldn't matter if it was cold or hot...that distance does not change with temp.
My suggestion on the ignition timing is that it may be too far advanced. This in itself would not cause any running problems with the engine, but it can make it harder to start when it gets hot. The suggestion to pump the accelerator 4-5 times and crank it is to allow the fuel to cool down the cylinder temp. If doing this helps get the engine turning/started, then you know you have too much ignition timing. 

If you have an ignition issue , solve it and make sure the car is timed correctly. As stated above to much advance will make a motor crank very very hard once it warms up. So hard in fact you may think you have a bad battery or bad starter.

Tomorrow I am going to a mechanic. We replace starters. He has a new one. It's a simple test. If will be fine turning it will mean that my starter is bad. Also check the cable connections. The setting timing point I have a problem. Or my lamp is broken or pulley with the sign has been plastered. I do not know how to write. :-) When everything is connected (one cylinder) sign indicates the delay (before) about 60-70 degrees which is unrealistic :-)

|UPDATED|4/10/2013 12:20:31 AM (AZT)|/UPDATED|

Wow! That's pretty far off!
Just to verify, your timing light should be connected to the front plug wire on the driver side. IF that is correct, then the most likely cause for the way off mark is that the outer ring of the balancer has spun on the center hub. It happens quite often, especially on older balancers, since the rubber connecting the outer ring and inner hub dries out and splits over time.
I would first check for Top Dead Center on the #1 cylinder(on the compression stroke), and then see how far off the mark on the balancer is. Once you find TDC, you could add the correct mark to the balancer, and try to set the timing from the new mark.