Did you let the wicks get good and saturated first? I usually let mine sit and absorb for 10 minutes or so before I start vaping on it, then I puff on it a few times like a cigar to get everything heated up and flowing. If you're chain vaping on a brand new head, it may not be wicking fast enough to keep up with you. Go gently with it a little while you break it in. Mine always hit better after they've sat overnight.
When you filled it, did you possibly get any juice down the center hole?. When you fire the battery, what kind of noise does it make? If it sounds like it's drowning in juice, unscrew the vivi from your PV and blow through the mouthpiece, holding a napkin under the battery connection to catch juice, until you can't blow anything else out.
What is the resistance of the head in the vivi, and what voltage is your battery?
Someone else will probably be able to chime in with better advice. I've only been using a vivi about two weeks, but it's been virtually problem-free for me, so I haven't had to do much troubleshooting. (Mine's a mini, but I think they're pretty much the same besides tank size? Someone will correct me if I'm wrong, I'm sure.

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