Ignition - Timing Adjustment Revised

9221mitsubishi01

NO.: TSB-89-16-004

DATE: July, 1989

MODEL: Mirage, Galant, Eclipse, Montero, Sigma V6


SUBJECT:
IGNITION TIMING ADJUSTMENT ON 4G61 AND 4G63 DOHC ENGINES, 6G72 ENGINE


PURPOSE
This bulletin describes a change to the ignition timing adjustment and inspection procedures on fuel injected vehicles that make use of the stepper motor type idle speed control. Whenever the ignition timing is being adjusted or checked for base timing, the Multi-Use Tester must be disconnected from the diagnostic connector. As a reference to this bulletin, please make the changes shown and write the TSB number in the TSB Revision box at the bottom of the affected Service Manual pages.

DETAILS OF CHANGE
To check or adjust ignition timing on MPI-equipped vehicles, the ignition timing adjustment connector must be grounded. This fixes the timing to a base value. On vehicles whose MPI system employs a stepper motor to control idle speed, plugging the Multi-Use Tester grounds a terminal in the diagnostic connector under the dash. This forces the MPI control unit to control base idle speed and stepper motor position, and override the timing adjustment connector. Therefore the Multi-Use Tester or ground wire must be disconnected from the diagnostic connector to set base timing.


SERVICE MANUALS AFFECTED
1989 Mirage Service Manual Volume 2, Page 8-176
1989 Sigma V6 Service Manual Volume 2, Page 8-162
1990 Eclipse Service Manual Volume 2, Page 8-165


1989 Galant Service Manual Volume 2, Page 8-217
1989 Montero Service Manual Volume 1, Page 14-63
Volume 2, Page 8-147





SERVICE MANUAL CORRECTION
(1989 Sigma V6 shown, typical)