Corrado L4-1781cc 1.8L SOHC SC (PG) (1990)
Knock Sensor: Technical Service Bulletins
Knock Sensor - New Checking Procedure
Group: 28
Number: 91-02
Date: November 30, 1991
Subject:
New knock sensor checking procedure
Model(s):
Corrado
1990-91 m.y.
The following checking procedure replaces the information found on page 28-11 of the Corrado Repair Microfiche.
Knock sensor, checking
Requirement
^ engine coolant temperature 80° C (176° F) minimum
^ check ignition timing (see Repair Group 28 for additional information) and record displayed value to use as a comparison later in this procedure
^ disconnect hose from Digifant control unit vacuum port
^ connect pressure tester VAG 1274 to vacuum port of control unit using auxiliary hose
^ start engine and let idle
^ coolant temperature sensor left connected
^ pump VAG 1274 to 1 bar of pressure (indicated on gauge)
^ slowly raise engine speed by opening throttle by hand until 2500 rpm is obtained
^ observe timing point at 2500 rpm
^ must be 5° ± 1° above the previously recorded value
If YES
^ knock sensor is OK
If 3° ± 1° below the previously recorded value