GM Chevy Mid-Size Cars 1964-1988 Repair Guide

Throttle Position Sensor (TPS)


See Figure 1

On feedback vehicles, the throttle position sensor is mounted in the carburetor body and is used to supply throttle position information to the ECM. The ECM memory stores an average of operation conditions with the ideal air/fuel ratios for each of those conditions. When the ECM receives a signal that indicates throttle position change, it immediately shifts to the last remembered set of operating conditions that resulted in an ideal air/fuel ratio control. The memory is continually being updated during normal operations.

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Fig. Fig. 1: Throttle Position Sensor (TPS)