My tach stopped working

Hello, I read that you're replacing "pertinent sensors" - but based on what testing? For tachometer operation, you would check for output at cavity 43 of the processor. Then, check for continuity of the wire at cavity 43 to the tachometer input. If all is good there, then you have a concern with the tachometer itself. Based on the vehicle running poorly, however, I would be focused on engine performance as a primary concern. How is engine timing? How is engine compression? Have you been able to monitor the cam and crank sensor operations using a diagnostic tool? Testing is required to narrow down your concern to the source.