Battery goes dead

Hello,
I have 92 LS400, w/traction control. It has many problems, power seats are not working (relays are making little sound), mirrors are moving only to up and down, left front speaker is making cracking sound, and battery is getting empty all the time, speedometer too is dead along with half fuel meter. But this is okay if I get the right diagrams and key to read them. Today, half of my cylinders stopped working. Engine started to stall and to smell like un-burned or leaking fuel. After stopping (first I was sure that my fuel is ending but after stopping at the gas station and noticing some smoke I think its not okay.