Engine - Stalls When Cold

90ford10

Article No. 90-10-3

STALL- 1.9L CFI - AFTER COLD START DURING A LONG DECEL TO A STOP

FORD: 1987-88 EXP 1987-90 ESCORT

INCOLN-MERCURY: 1987 LYNX


ISSUE: The engine may stall when it is cold, and the vehicle is driven under a long deceleration to a stop. This occurs because of unique idle speed adaptive conditions only on some vehicles.

ACTION: Set the engine throttle position sensor to specification by using the following service procedure.

1. Perform Key On Engine Off and Engine Running Self-Test. Service all codes. Refer to the appropriate Engine/Emissions Diagnosis Manual, Volume H for service details.

2. Install a breakout box and connect the processor to the breakout box.

3. Warm the engine to operating temperature.

4. With engine OFF...

a. Remove the air cleaner.

Figure 1:

b. Connect a jumper wire between the self-test input (STI) and the signal return pin on the self-test connector, Figure 1.

5. Turn the ignition key on, but do not start the engine. The idle speed control (ISC) plunger will retract within 10-15 seconds.

6. Disconnect the vehicle harness from the ISC motor.

7. Turn the ignition key to the OFF position.

8. Remove the jumper wire.

9. Start the engine and run it to normal operating temperature.

10. Check the idle RPM. It should be 600/650 RPM.

Figure 2:

11. Adjust the throttle stop adjusting screw, Figure 2, if the RPM is not within specification (600/650 RPM).

12. Turn the engine "OFF".

13. Install digital volt-ohm multimeter (DVOM) to pins 47/46 in the breakout box and set the DVOM on the 2-Volt scale.

14. Loosen the screws on the throttle position (TP) sensor.

15. Set the TP sensor to .825/.835 volts and retighten screws, Figure 2.

16. Start the engine and recheck the hardstop RPM (600/650) and the TPS setting (.825/.835 volts).

17. Turn the engine "OFF".

18. Reconnect the vehicle harness to the ISC motor.

19. Remove the breakout box.

20. Reinstall the processor to the vehicle harness.

21. Start the engine and test drive the vehicle.

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage
OPERATION DESCRIPTION TIME
901003A Reset Idle Speed 0.7 Hr.
DEALER CODING
BASIC PART NO. CONDITION CODE
DRIVE J9
OASIS CODES: 630000, 630100, 630103