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Standard Ignition AC21 Idle Air Control Valve
| Brand | Standard Ignition AC21 |
|---|---|
| Terminal Quantity | 2 |
| Terminal Type | Blade terminals |
| Fits | Ford, Lincoln, and Mercury · 77 vehicles |
Accurate airflow control. Polymer-blended magnet helps the pintle respond precisely for consistent operation.
High-torque stepping motor. Delivers strong output for dependable actuator performance.
Extended service life. Shielded ball bearing helps resist contaminants and wear.
Cross-references AP Exhaust 8490, Hitachi Automotive ABV0035 and HOLSTEIN 2IAC0008 for the same application. See all 17.
Idle Air Control Valve for Ford and Lincoln
Standard Ignition AC21 is an idle air control valve for select Ford, Lincoln, and Mercury applications from 1986-1993. It is built for accurate idle airflow control, helping maintain stable engine speed on vehicles such as the Ford Mustang and Lincoln Mark VII.
Key Features
- 2 blade terminals for straightforward electrical connection
- Polymer-blended, isotropic neodymium/iron/boron magnet for precise pintle movement
- High-strength stepping motor for consistent airflow control
- Shielded ball bearing motor design to resist environmental contaminants
- Load-tested actuator for added durability and dependable operation
- Manufactured with high-grade materials for extended service life
Detailed Description
The Standard Ignition AC21 idle air control valve regulates bypass air around the throttle plate to help the engine maintain the correct idle speed during cold starts, accessory load changes, and stop-and-go driving. This part number AC21 is engineered with a precise magnet and stepping motor assembly to control the pintle accurately, supporting smooth idle quality in Ford Mustang, Lincoln Mark VII, and other listed applications. This part cross-references Hitachi Automotive ABV0035 for the same application.
What It Helps Solve
- Rough or unstable idle
- Idle speed that drops too low or stalls at stops
- Idle flare or hanging idle after throttle release
- Idle quality issues caused by a sticking or worn IAC valve
- Driveability concerns during cold starts and accessory load changes
Installation Notes and Fitment
Fits 1986-1993 Ford Mustang, N/A. Fits 1986-1992 Lincoln Mark VII, N/A. Fits 1989-1991 Ford LTD Crown Victoria, N/A, w/ Calif. Emissions; Auxiliary Air Valve. Fits 1989-1991 Mercury Grand Marquis, N/A, w/ Calif. Emissions; Auxiliary Air Valve. Fits 1990 Ford Bronco II, N/A. Fits 1989-1990 Lincoln Town Car, N/A, w/ Calif. Emissions. Fits 1986-1988 Ford Thunderbird, N/A. Fits 1986-1988 Lincoln Town Car, N/A. Fits 1987-1988 Mercury Cougar, N/A. Fits 1986-1987 Lincoln Continental, N/A. Fits 1986 Mercury Capri, N/A. Fits 1986 Mercury Cougar, N/A, Fitment: Primary with California Emissions.
Before installation, confirm the connector style matches the 2-terminal blade design and verify the vehicle’s emissions configuration, especially on California-emissions applications. Inspect the throttle body and air passages for carbon buildup so the new valve can control airflow accurately.
Quality Assurance
Standard Ignition manufactures this idle air control valve with durable materials and load-tested components to support consistent operation and long service life. The AC21 is built to meet the demands of daily driving in the listed Ford, Lincoln, and Mercury applications.
| Year | Make | Model | Transmission | Liters | Cylinders | Notes |
|---|---|---|---|---|---|---|
| 1993 | Ford | Mustang | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1993 | Ford | Mustang | — | 5.0L | V8 | Compatible with various car models. |
| 1992 | Ford | Mustang | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1992 | Ford | Mustang | — | 5.0L | V8 | Compatible with various car models. |
| 1992 | Lincoln | Mark VII | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1992 | Lincoln | Mark VII | — | 5.0L | V8 | Compatible with various car models. |
| 1991 | Ford | Country Squire | Automatic | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1991 | Ford | Country Squire | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1991 | Ford | LTD Crown Victoria | Automatic | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1991 | Ford | LTD Crown Victoria | Automatic | 5.8L | V8 | Fitment: Primary with California Emissions. |
| 1991 | Ford | LTD Crown Victoria | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1991 | Ford | Mustang | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1991 | Ford | Mustang | — | 5.0L | V8 | Compatible with various car models. |
| 1991 | Lincoln | Mark VII | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1991 | Lincoln | Mark VII | — | 5.0L | V8 | Compatible with various car models. |
| 1991 | Mercury | Grand Marquis | — | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1991 | Mercury | Grand Marquis | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1990 | Ford | Bronco II | — | 2.9L | V6 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1990 | Ford | Country Squire | Automatic | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1990 | Ford | Country Squire | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1990 | Ford | LTD Crown Victoria | Automatic | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1990 | Ford | LTD Crown Victoria | Automatic | 5.8L | V8 | Fitment: Primary with California Emissions. |
| 1990 | Ford | LTD Crown Victoria | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1990 | Ford | Mustang | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1990 | Ford | Mustang | — | 5.0L | V8 | Compatible with various car models. |
| 1990 | Lincoln | Mark VII | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1990 | Lincoln | Mark VII | — | 5.0L | V8 | Compatible with various car models. |
| 1990 | Lincoln | Town Car | — | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1990 | Mercury | Grand Marquis | — | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1990 | Mercury | Grand Marquis | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1989 | Ford | Country Squire | — | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1989 | Ford | Country Squire | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1989 | Ford | LTD Crown Victoria | — | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1989 | Ford | LTD Crown Victoria | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1989 | Ford | Mustang | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1989 | Ford | Mustang | — | 5.0L | V8 | Compatible with various car models. |
| 1989 | Lincoln | Mark VII | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1989 | Lincoln | Mark VII | — | 5.0L | V8 | Compatible with various car models. |
| 1989 | Lincoln | Town Car | — | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1989 | Mercury | Grand Marquis | — | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1989 | Mercury | Grand Marquis | — | 5.0L | V8 | w/ Calif. Emissions; Auxiliary Air Valve |
| 1988 | Ford | Mustang | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1988 | Ford | Mustang | — | 5.0L | V8 | Compatible with various car models. |
| 1988 | Ford | Thunderbird | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1988 | Ford | Thunderbird | — | 5.0L | V8 | Compatible with various car models. |
| 1988 | Lincoln | Mark VII | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1988 | Lincoln | Mark VII | — | 5.0L | V8 | Compatible with various car models. |
| 1988 | Lincoln | Town Car | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1988 | Lincoln | Town Car | — | 5.0L | V8 | Compatible with various car models. |
| 1988 | Mercury | Cougar | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1988 | Mercury | Cougar | — | 5.0L | V8 | Compatible with various car models. |
| 1987 | Ford | Mustang | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1987 | Ford | Mustang | — | 5.0L | V8 | Compatible with various car models. |
| 1987 | Ford | Thunderbird | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1987 | Ford | Thunderbird | — | 5.0L | V8 | Compatible with various car models. |
| 1987 | Lincoln | Continental | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1987 | Lincoln | Continental | — | 5.0L | V8 | Compatible with various car models. |
| 1987 | Lincoln | Mark VII | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1987 | Lincoln | Mark VII | — | 5.0L | V8 | Compatible with various car models. |
| 1987 | Lincoln | Town Car | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1987 | Lincoln | Town Car | — | 5.0L | V8 | Compatible with various car models. |
| 1987 | Mercury | Cougar | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1987 | Mercury | Cougar | — | 5.0L | V8 | Compatible with various car models. |
| 1986 | Ford | Mustang | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1986 | Ford | Mustang | — | 5.0L | V8 | Compatible with various car models. |
| 1986 | Ford | Thunderbird | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1986 | Ford | Thunderbird | — | 5.0L | V8 | Compatible with various car models. |
| 1986 | Lincoln | Continental | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1986 | Lincoln | Continental | — | 5.0L | V8 | Compatible with various car models. |
| 1986 | Lincoln | Mark VII | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1986 | Lincoln | Mark VII | — | 5.0L | V8 | Compatible with various car models. |
| 1986 | Lincoln | Town Car | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1986 | Lincoln | Town Car | — | 5.0L | V8 | Compatible with various car models. |
| 1986 | Mercury | Capri | — | 5.0L | V8 | Primary application for specific vehicle models ~ Idle Air Control Valve |
| 1986 | Mercury | Capri | — | 5.0L | V8 | Compatible with various car models. |
| 1986 | Mercury | Cougar | — | 5.0L | V8 | Fitment: Primary with California Emissions. |
| 1986 | Mercury | Cougar | — | 5.0L | V8 | Compatible with various car models. |
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