I (my car) has a problem. It's an '95 and it is shaking from time to time. It seems that the car shakes when it wants to shift but it sometimes happens when the car doesn't have to shift. When i then accelerate then the shaking is over for that moment. I did read out the errorcodelog by turning 2 times the ignitionkey and the code that came up was code 11. I did go to the dealer here and they couldn't read out the computer because it is an early model of the 2G. I must say that i did fill the Automatic transmission not long ago and no it was not to much oil . But i did fill with an other ATF number (instead of ATF2,ATF3 or instead of ATF3,ATF2 in it).
It says code 11 is for alternator. However I dont see how that would cause your car to shake but rather not start or stay running, unless it is just on the edge. I have a 95 and the dealer can read my codes without a problem, You need a new dealer if they told you they cant.
I would suggest you check your vac hoses for leaks and clean out the carbon build-up in your engine. These could easily cause a rough idle or a loopy idle.