Severe engine power loss betw idle and 2k RPMs

Hello,

A few days ago I was driving home from work and all my dash lights came on, so having read alternator-related posts on this board beforehand I went ahead and just ordered a new one from the parts shop and put it in. At about this same time, I have an extreme loss of power under medium and heavy acceleration if the RPMs are between idle and 2000 or so. If you mash the accelerator down, it lags around for a second or two then reaches 2000 RPMs and blasts off. In the same way that most SVXs feel cantakerous when cold, this is how it feels all the time between that rev range. Even at constant speed in overdrive, it is tough to pull hills.
I cleaned out the throttle body to see if that would help, but it is still there. I've read about the ECU crush mod, but that seems to apply only to acceleration and not to general power loss. I've searched and read a few other posts with my same symptoms, but no one ever posted a solution (except for the throttle body clean). The problem just seemed to happen all of the sudden. Any advice?

Thanks,