The problem I have with Capt'n's test procedure is that with the injectors removed, pressure load on the outlet ports of the fuel distributor is about 0. A leak will likely not show itself in this test, where it would occur readily if the injectors were attached.
I'd say your fuel distributor plunger shaft is almost certainly the source of your pooling, and it is safe to say both that this is not normal, and the source of your smoking. There is a post here with pictures of 6 o-rings to the separate distribution chambers of the fuel distributor, if you can find it. I'll bet if you replaced those it would solve your problem. You'd need to find an appropriate material - ordinary Buna-N o-rings won't do it.
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7