Engine - Erratic Idle Speed

Article No. 86-7-11


ENGINE IDLE SPEED - 3.8L - ROAD SPLASH ON 12-PIN CONNECTOR

FORD 1984-85 MUSTANG, THUNDERBIRD, LTD

LINCOLN-MERCURY 1984-85 CAPRI, COUGAR, MARQUIS

CALIBRATIONS: All 3.8L without air conditioning

WARNING: This modification is authorized only for the listed engines. Performing this modification on other engine calibrations is unauthorized and could create liability under applicable federal or local laws.

A random change in engine idle rpm can be caused by electrical leakage at EEC wire harness connectors. To service this concern, cut and tape the "ACC" signal wire.

A 12-pin connector (C-201) connects the 14401 harness to the 14290. Road splash can enter this connector and cause an erroneous signal to air conditioner circuit No. 347 on vehicles without air conditioning. This signal may result in the Idle Speed Control Actuator (ISCA) being activated. This condition may occur with transmission in neutral or in drive; it may occur at any speed.

1. Confirm that the ignition switch is in the "off" position.

2. Remove the processor (12A650) from the mounting bracket.

3. Locate the No. 347 (black with yellow hash) going to pin No. 10 at the 60-pin connector. Cut this wire at a point approximately six inches from the 60-pin connector.

4. Tape (insulate) each cut end of No. 347 wire. Fold harness end of No. 347 wire over the wire bundle and secure with additional tape. This will allow splicing of the wire back into the wire harness if air conditioning is installed at a future date.

5. Reinstall the processor in the mounting bracket.

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP12650A86
TIME: 0.4 Hr. DLR. CODING: Basic Part No. 12A581 - Code: N5