Were does the signial for the speedo on the insterment pannel come from? ecm or the vss? I am going to switch to a carb and was wanting to take the computer out but still need to run my stock speedo for now. Also does the tach or anyother gauges run off the computer? can I take out the computer and still run the vss? Sorry I am just really confused.

Thanks

 

Poncho,

The speedo will read teh VSS pulses directly, so you don't need the ECM for that. The tachometer reads the distributor primary side switching pulses directly (through a tach buffer module), so you don't need an ECM for that. The temperature, oil pressure, fuel guage, and voltmeter are also independent of the ECM. However, you will need the ECM to operate the fuel pump, torque converter lockup, ESC, EGR, EVAP canister purge, and A.I.R. system if you intend to keep using any of those. Those can all be operated in other ways, but the ECM does that from the factory. You would need an array of temperature vacuum switches to operate the EGR, EVAP, and A.I.R., an older style distributor that doesn't use an ESC, and a means to operate the fuel pump, like through the auxilliary oil pressure switch. The TCC lockup would have to be done with a custom logic module and some creative wiring, or an aftermarket TCC control.

 

Thanks vader that is exactly what I needed to know!!!! I am not going to be running any of those. I am switching to a th350 or 400 so I won't need the lockup.