A sewage pump in my basement is 7 feet from the shower drain and 2 feet from the water closet. The only vent is from the sump pump which runs 20 feet horizontally to an outer wall then goes vertically till it stops just below the soffit on the ground floor. Toilet never flushed properly so what must be done, now that I have the bathroom ready for total refurbishing? The shower waste is 2" and 36" from trap to an el that drops below concrete right near the lav's vertical drain which ends in the concrete into what might be an 1.5" trap. They may join under the concrete then go to the sump. I looked down the closet drain, all I see is a 3" el with no connections. Funny thing is, the closet drain is pointed 90 degrees away from the sump? The toilet is not clogged, I used to work with a plumber so I know about the holes you speak of. The vent may be the problem. It's 2" and rises into the joists, runs 3 els and I think goes as I stated. I was wondering if I might cut the vent near the joists, reinstall the john and flush it and see if it works. It's is gravity operated. The vent isn't code if it's not through the roof and I'm not so sure that long a horizontal run makes a good vent. We want to sell the house so we need to be up to code and functional. I was thinking of attempting to run a 1.5" vent through the roof if my experiment works. What do you think?