On my intake valve I have an open PVC valve and it has a vacuum leak somewhere I can't find the leak anywhere if Make it back to my farm tonight I'll post pictures

 

pcv valve should have a hose that goes to the back of the carb area... i just found some vacuum leaks by using a little propane torch, you dont light it but open it up and go around any areas that might might be causing the leak with the engine running, the engine will suck it in thru the leak and accelerate.