Forma Festiva Automatic Full Injection 2000

Hello friends, I'm new here and I hope you can help me solve these problems.

The issues I'm having with this vehicle are the following:

- When the engine has been idle for a while, for example, 2 hours, I start the engine, but when I press the accelerator, it seems to lose power and tries to stall. If I put it in gear, it starts to shake. But after a while (5 to 10 minutes), the engine runs smoothly and works perfectly in both gear and in neutral. Why does this happen?

- The previous owner installed a system on this vehicle where the electric fan turns on automatically when the key is turned and stays on while the key is in the ignition. Some people tell me it's a valve that controls the electric fan that isn't working, but could you please tell me how the electric fan should be connected correctly and where this valve is located?

Thank you, I look forward to your help.