My Jeep idles fine, and drives fine other than this issue (no rough idle), but regardless of what gear it's in, it drops back down to idle(ish) speed when it hits a certain RPM point... I can't tell you what point, because my car doesn't have a tach. On level ground, it'll hit exactly 55 MPH max.

But regardless of what gear my car's in/going into, it just bogs/bucks at a certain RPM point.

It's been sitting for 6 years before this week, so I'm hoping there's just crud in the fuel filter, or the pickup in the tank... But being that it's bucking/bogging at an exact point, I'm inclined to think it's a sensor?

Please tell me it's not a fuel injector problem...
I think I'm taking it to the shop tomorrow, but I'd like to know what you all think. But... I plan to upgrade to the Volvo 746 injectors, so I don't want to have to deal with the injectors yet.