带有字符集的IE8特殊字符

Question

I have a big problem with IE8

I have field TextArea, user write everything use lot of characters ç àèì áéí, show ok in textarea, debug in Javascript and Jquery ok too. but when I send to MVC controller change characters special for "?"

I tryed in Chrome and FF IE 10 or 11 , its ok, problem is only IE 8

I trying post using $.post,

$.ajax({
        type: "POST",
        url: "my controller",
        dataType: "json",
        data: '{}',
        contentType: "application/json; charset=UTF-8", //I use too for test ISO-8859-1
        success: function (msg) {
                alert(msg);
        },
        error: function () {
                alert("Error!");
        }
});

I put too in master page and this page:

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

I tried create a Form too, but I try to send to form but happen same thing.