idles but won't rev
 

I replaced the timing belt and heads (bent valves) on my 1999 Passat. When I turn it on runs rough. It will idle ok, about 800 rpm, but stumbles and labors when I rev it. The timing seems to be off using a timing light (early). I'm thinking cam position sensors but I don's know. Any help?

if throttle body cleaner is sprayed down inlet revs good, have replaced fuel filter, temp sensor still no result.