Chrysler Town & Country erratic tachometer

I have a 1998 Chrysler Town & Country 3.8L, and once the engine warms up the tachometer starts jumping around, and occasionally the engine cuts off while the RPM’s are being erratic. We have replaced the ECM, other sensors, including ones pertaining to the transmission.

Does anyone know how to fix this? We need to make this car last at least another year.

I would suspect the engine speed sensor or the BCM possibly.