The throttle position sensors mission on a 1988 Nissan pickup is to signal the engine management computer of the position of the throttle plate (which coincides with position of the gas pedal) and the rate at which it is opened. The computer uses this information to determine load and adjust the timing and fuel injection to accommodate demand. The throttle position sensor on this model has a problem with moisture. It will fail if it gets wet and cause off-idle hesitation and surging. A bad TP sensor will cause an automatic transmission to change shift points and cause erratic operation.
Instructions
- 1
Remove the air cleaner with a socket and ratchet. Locate the throttle position sensor. It is located on the throttle body opposite the throttle linkage. Connect the voltmeters black lead to a good ground on the intake manifold.
2Use the sharp tip of the voltmeters red lead to pierce the center wire in the connector on the sensor. There are three wires in a straight line from left to right. The center wire is the signal wire.
3Turn the ignition key to the On position without starting the engine. Observe the voltage displayed. It must be 0.4 to 0.5 volts. Loosen the two bolts securing the sensor to the throttle body using the appropriate socket.
4Watch the voltage on the voltmeter and at the same time slide the sensor slightly to the left or right until the voltage is in the right range. Lock the sensor down by tightening the two small bolts with a socket. Do not overtighten them or they will strip. Turn off the ignition switch and install the air cleaner.
