1989 gmc k15 4x4 automatic 3 problems

i have 3 concerns the first one my speedo only works when it wants ive already changed speed sensor took cluster out and cleaned all connectors . yet i got no change. number 2 fuel gage only works from 3/4 full to full another words at 3/4
im emty between 3/4 and full is half tank and full is full .I already changed sending unit and cleaned contacts on gage . no change. and last adle gos up to 1500 rpm i replaced IAC and TPS and MAP Sensor and EGR and some times it blows black smoke burn rich. can any body help. thanks

Is the high idle all the time? If so, check the TBI gasket for a leak. Spray TB cleaner around the base, especially at the rear of the TBI unit. If the idle changes, the TBI gasket should be replaced.

//2000CAYukon

cool thank you so much i will check it