teckel:
Use the KISS rule. First, use one sensor. Secondly, connect a trigger and echo sensor to that one sensor. Run a test to see if that works. If it works, add stuff back in till it no longer works and that's your problem. If it still doesn't work, make it even more simple (like use the example sketch only with nothing else). Still doesn't work, remove the shield, etc.There's no way anyone can diagnose your problem, as it's not a library problem. But, it sounds like you're trying to run before you walk. Walk first, then run. Trying to do this quickly is basically the problem.
Tim
I didn't said it was a library problem but didn't know where to ask. Today I will try what you said, hope it's a l293d shield problem, as i see on the internet, it uses almost all digital pins, if so, i will connect them to analog pins. Is there anyway to stop them and read values one at a time? For example, if i have 4 sensors - 2,3,4 to be OFF and the first sensor to be actived, then 1,3,4 etc
As i can see on other forums, they need to connect to different pins to have a consistent reading. I will come with a replay later this day. thank you!