Mirage L4-1597cc 1.6L DOHC (1990)
Throttle Body: Testing and Inspection
To determine if the internal passages of the throttle body are clear and functioning properly, perform the checks listed below.
These checks are to be performed with the engine coolant temperature at 176 - 205°F (80 - 95°C).
EGR VALVE, CONTROL VACUUM CHECK:
EGR Control Vacuum Source
1.
Disconnect the vacuum hose from the throttle body EGR vacuum fitting and connect a hand vacuum pump to the fitting.
EGR Port Vacuum Curve
2.
Start the engine and check to see that, after increasing the engine speed, vacuum raises proportionate to engine speed.
NOTE: If there is a problem with the changes in vacuum in this test, it is probable that the throttle body requires cleaning. Refer to COMPONENT
REPLACEMENT AND REPAIR PROCEDURES
For diagnosis and testing of the motor position sensor (MPS), idle switch, throttle position sensor (TPS) and the idle speed control (ISC) servo, refer to
COMPUTERIZED ENGINE CONTROLS.
