I finally did it!!!
In my case the problem was at the last step where i had my output from the hamc-sha1() and i was trying to base64 the output.
The output of the hmac-sha1 was like this 890148acbb265a53fd3479c75bb2d8866852f196
so when i was trying to convert into base64 this i was getting something like this ODkwMTQ4YWNiYjI2NWE1M2ZkMzQ3OWM3NWJiMmQ4ODY2ODUyZjE5Ng==.
That was something that put me in thoughts because at the twitter guide on how to make an oauth signature (bottom of the page) the author give as a much smaller output like hCtSmYh+iHYCEqBWrE7C7hYmtUk=
So i searched and find that the output of hmac-sha1 has to be interpreted as a hex before converted to base64