Ill continue to check what you said, here is some explaination:

I said everything electrical is good cause I already tested it with and without the EHA connected = no differance,

I changed the fuel distribturor cause I tought it was the problem.

The lamda is good = 50% with the correct variation BUT it smells fuel at the exhaust! How can the air/fuel ratio be good but it still smell gas! I really think it is due to the too low spark voltage...