From my experiences, best way to decarbon a vehicle is to put some fuel cleaner additive in the tank and drive the car for a couple of hours on the interstate on one continuous cruise situation. Not something that happens immediately even with all of the magic potions of modern time. Carbon buildup is not usually a power loss situation, though, unless it's really bad, which would also raise the octane requirement of the engine well beyond what anything but race fuel would match.
That kill switch was probably someone's inexpensive anti-theft device. If it's causing a power loss to the ignition, that will result in lots of flaky things--including power loss--due to a weak spark. The Chrysler factory electronic ignition, if you have one, is more sensitive to voltage (especially the beloved Orange Box that comes with the Mopar Perf Electronic Ignition Kit) and if the voltage is not at the minimum level, it won't fire the plugs even as it turns over fast enough like it ought to have enough power to fire off. I might recommend just taking that kill switch out of the circuit and also checking voltage to the ignition system.
Other than that, might be a muffler restriction issue. Don't forget to check all of the tune-up settings, too, to make sure they are still in spec. If, per chance, the carb uses metering rods (i.e., AFB, AVS, T-Quad) run by a power piston(s), if the spring under the pistons has broken, the metering rods will not move from the "economy" position and result in low power once the accelerator pump shot is expended (except on the T-Quad which has a dedicated cam/pin mechanism for the power piston).
Back to the Home of the Forward Look Network