Secondary Inputs

SECONDARY INPUTS
These inputs will not prevent the engine from starting, however they do perform important functions and must not be neglected.




Coolant temperature sensor
This sensor give a variable resistance with respect to temperature. This allows the ECU to trim the ignition timing dependent on coolant temperature. The table below gives approximate resistance (in ohms) against temperature.

Air temperature switch
This switch is a bi-metal unit (located on the back plate of the 'A' bank air cleaner) to switch on at 75°C this performs the function of retarding the ignition timing at high air inlet temperatures.

Throttle idle switch
This switch enables the ignition ECU to sense when the throttle is in the closed position, the engine is idling or in a overrun condition. It is therefore important that the contacts of this switch are 'CLOSED' when the throttle is in the closed position.




Map select link
This link permits the selection of either of the two ignition maps contained in memory. If the link is in place the ignition map suitable for 95 octane fuel is selected, and if the link is removed the ignition map suitable for 91 octane fuel is selected.