In newer cars with electronics the engine has a sensor which pulses every revolution. The computer measures the time between the pulses and outputs a signal to the gauge in the dash. The larger the signal, the higher up the gauge goes.
In older cars the tachometer receives a similar signal, but from part of the ignition coil.
Revo
Visit www.votex.ltd.uk They can remap your car with Revo software.
Electronic Revo
Revos are made at the Revo factory.
Toyota Revo was created in 1998.
The revo 3.3 is anywhere from $400-$800.
This might not help... Get a new one.
Revo Soekatno was born on 1975-08-02.
Revo Jõgisalu died on 2011-08-30.
Revo Jõgisalu was born on 1976-07-09.
Sega Rally Revo happened in 2007.
3 turn overs