i sealed with silicon the windscreen seal and it worked well.
now i have a wet footwell again. Any suggestion?

 

Have you tried clearing out the scuttle drains?
I had the same issue with my 94.
Very common issue with these cars.

 

Wich one? I cleared the ones of the A and B pillar in the front of the roof…

 

The drain lines for the wiper motor scuttle run down into the interior on both sides of the transmission tunnel.
I DON'T recommend blowing them out with compressed air.
The high pressure will blow them off the fittings.
Better to use a wire pushed down from the scuttle.
Also make sure the bottom end of the hose is still out the floor.
Once you are sure the lines are connected and clear you can pour some water thru the scuttle.

 

A few suggestions:
1. Take the floor mats out then climb in with a friend spraying the car with the hose to try to locate where the water is coming in from.
2. If that doesn't help then open the hood and pull the rubber tubes from the wiper motor box and clean them and the connecting metal tubes.
3. Remove the wiper motor and clean the box of any built up debris.
4. Clean the rubber weatherstripping along the 'A' pillar
5. Clean the drain tray and path that comes off the 'A' pillar as it goes down along the front edge of the door frame
6.Remove the little 'cheek' panels with the vents by your calf and make sure the drain tubes coming off the Delenaire III unit are connected.

 

I think you may be confused:
The drain tubes from the wiper motor scuttle run forward into the engine bay each side, and out though the wing by the front wheels.

You may be thinking of the drains for the consenste from the aircon? There is a shallow tray under the aircon unit which has two small drain tubes from it that run down each side of the transmission. These can only be accessed from under the car and poking them ckear with a bit of stiff wire is a good idea. They are not easy to see, but here are some pics showing the RHS aircon drain tubes: