DQ - Testing Notes

NOTE: You should enter this Pinpoint Test only when you have been directed here from Quick Test.

REMEMBER

To prevent the replacement of good components, the following non-EEC areas may be at fault:

- Idle speeds/throttle stop adjustment.

- Binding throttle shaft/linkage.

- Choke/high cam system, if equipped.


This Pinpoint Test is intended to diagnose only the following:


- TP Sensor

- Sensor harness circuits: VREF, TP, and SIG RTN

- Processor Assembly


DESCRIPTION

Throttle Position Sensor:

The Throttle Position (TP) ensor is a potentiometer that provides a signal to the Electronic Control Assembly (ECA) that is directly proportional to the amount of fuel being delivered from the fuel injection pump. Unlike a gasoline engine TP sensor, the sensor is bolted to the fuel injection pump and is actuated by the throttle lever.