Hi,
Since a couple of week, my transmission is doing some crazy thing.
When the engine is hot(usualy after at least 20minutes of city driving), i feel the engine reacting strangly when i remove my feet of the gaz pedal or when i press the gaz pedal (slowly pressing it). Soon as this trouble start, When my engine goes under 40km/hr (25miles/hr) the engine start shaking roughly. And then when i need to stop the car (at a red light). oh my god, i does some kind of sound that i didnt know an engine could make, the kind of sound that scare you if it's your car. and just before the car is completly stopped, the card dies. Then i restart it (it always restart well), but takes 2 to 10seconds ton reach have an stable idle, and when i put i to drive THE CAR DIE !!!!. its always the same thing.
Now i have 2 options
1. Wait 5min for the car to cool down
2. When i put to drive, quickly press the gaz pedal to the near end, the car will run strangly for a couple of seconds but it will work.
After i RE-start the car, the trouble will stay hidden for 4-5 min and then , the same story restart

Anyone got ideas?
Thanks

Part II
Here's why I think it's the transmission

When the car is on PARK. Sometimes, the light next to P (on the transmission) goes off or half on. When this happening, the engine RPM move between 500 and 1000RPM. To solve this, i juste have to press that light, and it will come on again and the trouble stop (really strange way to solve the problem). Sometimes, the light stay on for a minutes (less or more) and then the trouble restart.

But after my car dies, like what i said in the fist post
this light dosen't come on anymore, after a let the car cool down a couple minutes, the light may come on and then the car no longer die when i put it into the Drive.

And then my car will work for a 5min, then the trouble will start again.

Anyone got ideas?

Transmission wouldn't be my first guess actually. I would say fuel pump as the most probable culprit from everything you described.

Problem Solved!

the problem was the lockup switch in the transmission, the guy told me it's a very usual problem on the 3speed gm transmission, it cost me 150$ CAN

That was going to be my guess, your torque converter was locking up and since you were at a stop or had the brakes on it would kill the motor before it got you moving. I've heard you test this by unplugging the electrical connector on the transmission. glad to hear you got it fixed.