Hey, i have 1992 300ce 150k miles, 3.0L m104.
I had a sound system in the car, it was 1200watts rms, 2400watts peak.
Acdelco battery 775 cold crank amps.
Aftermarket alternator, I think it was at 70amps.

Okay my problem is the throttle adjustment is completely off. When the car is cold the idle is 700-rpm. When worm it will drop to 500-rpm in park and 450-500-rpm in drive. Now at these low rpms the alternator does not charge my battery (all my dash lights turn on) when i accelerate the lights go away and it charges. Now while i'm driving the the battery goes to about 13.5 volts, when I come to a stop it goes down to 12 volts. When I change my battery it last for about 4-5 months, then after that it goes from 13.5 volts to about 10 volts, then my battery just dies.

My shifting is off as well, at full throttle the car starts to slip at 4500-rpm until i let off the gas so it upshifts.

Now my ideas are to adjust the throttle linkage and kick-down cable, FIND a high output alternator and a good battery.

Any ideas, suggestions, tips or something. I have been dealing with this problem for about one and a half years now, It seems like no matter what I do the problem wont go away.

My budget is very small too, since I'm a full time student

Thanks in advance.