Use :set synmaxcol=0
para remover o limite ou escolha qualquer valor grande.
Aviso: essa configuração pode introduzir um atraso de redesenho significativo.
Vim documentation: options - synmaxcol
'synmaxcol' 'smc' number (default 3000) Notes: local to buffer, not in vi
Maximum column in which to search for syntax items. In long lines the text after this column is not highlighted and following lines may not be highlighted correctly, because the syntax state is cleared. This helps to avoid very slow redrawing for an XML file that is one long line.
Set to zero to remove the limit.