Where to start? Off the line is boggy., But only sometimes... Options

[Nogoodwithusernames]

Haven't been on much lately, but I have had the 914 out a couple times when the weather has been nice, and have noticed that often (but not every time) when pulling away from a stop it's very boggy and low on power and won't pick up revs, sometimes even cuts out, if I rev it a bit before starting off it helps immensely. And once it gets going it also picks up in power and immediately revs much more freely.

It has semi-recently had a couple vacuum lines replaced and an ignition tune up (though the FLAPS didn't have the right heat spark plugs, off by one heat range)

Idle seems good and is pretty steady around 900, cruising seems to get some boggy-ness occasionally too, where I'll feel a bit of a drop in power then feather the throttle and it'll be fine again for a bit.

I don't know how soon I'll get around to trouble-shooting, we are trying to move currently, but I would like to be somewhat prepared for when I have a couple free minutes to start picking at it.

Any idea on what systems or components I should start with?