any 6 pak gurus out there?

alright.. I will check for leaks, brian6, what makes you think the pv is open all the time? I will ck the power valve as well. this one has me stumped .my ta 340 six ran like a swiss watch.all my other 340s also ran well. this one is giving me a run for my money..i am determined to get it to run right.thanks for all the suggestions.