Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine - Intermittent/Constant High Idle Speed
1986 Ford Aerostar V6-183 3.0LSECTION Engine - Intermittent/Constant High Idle Speed
87ford25
Article No. 87-25-7
IDLE - HIGHER THAN NORMAL - VEHICLES WITH THROTTLE POSITION SENSORS BUILT BEFORE 05/28/87
FORD: 1985-87 TEMPO 1986-87 TAURUS, CROWN VICTORIA 1986-88 MUSTANG, THUNDERBIRD
LINCOLN-MERCURY: 1985-87 TOPAZ
1986-87 COUGAR, SABLE, GRAND MARQUIS, CONTINENTAL 1986-88 MARK VII, LINCOLN TOWN CAR
LIGHT TRUCK: 1985-87 AEROSTAR, RANGER
ISSUE: Intermittent or constant higher than normal engine RPM at idle may be caused by throttle position sensors built before 05/28/87 (date codes of 7E27 or before). Service codes "23", "53", and "63" may or may not be displayed during Self-Test.
ACTION: To correct this, install a new throttle position sensor with a date code after 7E27. Refer to the following service procedure.
1. Check for vacuum leaks and repair if required.
2. If a vacuum leak was repaired see if the unsatisfactory idle condition is still present. If corrected, stop here. If still present, proceed to Step 3.
3. Make sure the accelerator linkage is not binding. If binding, repair as required and see if unsatisfactory idle condition has been corrected. Proceed to Step 4 if condition is still present.
4. Reset the idle hard stop to specification. Refer to the Engine/Emission Diagnosis Shop Manual, Volume H.
5. Perform EEC IV Self-Test. If service codes are present, service as required. Refer to the Engine/Emission Diagnosis Shop Manual, Volume H.
6. Check the wire harness continuity by performing the "WIGGLE TEST".
7. Disconnect the throttle position sensor from the wire harness and inspect the connectors for terminal or pin damage.
8. If wire harness has connector pin push out, service as outlined in TSB 85-14-12. If wire harness pins are OK, or symptom is still present, proceed to Step 9.
9. Install a new throttle position sensor with a date code on or after 7E28 (May 28, 1987), Figure 6.
OTHER APPLICABLE ARTICLES: 85-14-12
WARRANTY STATUS: Eligible Under Emissions Coverage
OPERATION: SP872507A
TIME: 1.3 Hrs. - 5.0L Crown Victoria/ Grand Marquis, Mustang, Thunderbird/Cougar, Mark VII, Continental, Lincoln Town Car
1.3 Hrs. - 2.5L Taurus/Sable 1.4 Hrs. - 2.3L OHC/2.3L HSC Mustang, Tempo/Topaz
1.7 Hrs. - 2.3L OHC/2.3L Turbo Thunderbird, Ranger
1.8 Hrs. - 2.3L OHC Aerostar DLR. CODING: Basic Part No. 9B989 - Code: 09
Article No. 87-25-7
IDLE - HIGHER THAN NORMAL - VEHICLES WITH THROTTLE POSITION SENSORS BUILT BEFORE 05/28/87
FORD: 1985-87 TEMPO 1986-87 TAURUS, CROWN VICTORIA 1986-88 MUSTANG, THUNDERBIRD
LINCOLN-MERCURY: 1985-87 TOPAZ
1986-87 COUGAR, SABLE, GRAND MARQUIS, CONTINENTAL 1986-88 MARK VII, LINCOLN TOWN CAR
LIGHT TRUCK: 1985-87 AEROSTAR, RANGER
ISSUE: Intermittent or constant higher than normal engine RPM at idle may be caused by throttle position sensors built before 05/28/87 (date codes of 7E27 or before). Service codes "23", "53", and "63" may or may not be displayed during Self-Test.
ACTION: To correct this, install a new throttle position sensor with a date code after 7E27. Refer to the following service procedure.
1. Check for vacuum leaks and repair if required.
2. If a vacuum leak was repaired see if the unsatisfactory idle condition is still present. If corrected, stop here. If still present, proceed to Step 3.
3. Make sure the accelerator linkage is not binding. If binding, repair as required and see if unsatisfactory idle condition has been corrected. Proceed to Step 4 if condition is still present.
4. Reset the idle hard stop to specification. Refer to the Engine/Emission Diagnosis Shop Manual, Volume H.
5. Perform EEC IV Self-Test. If service codes are present, service as required. Refer to the Engine/Emission Diagnosis Shop Manual, Volume H.
6. Check the wire harness continuity by performing the "WIGGLE TEST".
7. Disconnect the throttle position sensor from the wire harness and inspect the connectors for terminal or pin damage.
8. If wire harness has connector pin push out, service as outlined in TSB 85-14-12. If wire harness pins are OK, or symptom is still present, proceed to Step 9.
FIGURE 6:
9. Install a new throttle position sensor with a date code on or after 7E28 (May 28, 1987), Figure 6.
OTHER APPLICABLE ARTICLES: 85-14-12
WARRANTY STATUS: Eligible Under Emissions Coverage
OPERATION: SP872507A
TIME: 1.3 Hrs. - 5.0L Crown Victoria/ Grand Marquis, Mustang, Thunderbird/Cougar, Mark VII, Continental, Lincoln Town Car
1.3 Hrs. - 2.5L Taurus/Sable 1.4 Hrs. - 2.3L OHC/2.3L HSC Mustang, Tempo/Topaz
1.7 Hrs. - 2.3L OHC/2.3L Turbo Thunderbird, Ranger
1.8 Hrs. - 2.3L OHC Aerostar DLR. CODING: Basic Part No. 9B989 - Code: 09
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.