Buy Mercury Mariner Fuel Injection Throttle Bodys

The throttle body sits between the air filter box and the intake manifold. Inside is a butterfly plate that opens wider when you press the gas pedal (or when the electronic throttle control, "ETC," tells it to). A position sensor and tiny electric motor adjust the plate hundreds of times per second so the engine always gets the air it needs. When the part sticks, the Mariner can shake at idle, stall, lose power, or illuminate the wrench/check‑engine lamp. (carburetor-parts.com)

Ford's torque‑based ETC strategy "uncouples" pedal angle from throttle angle. Two processors inside the power‑train computer estimate driver demand, compare it with real torque, and move the motor accordingly for the best mix of pep and fuel savings. (Workshop Manuals)
Sensors track accelerator‑pedal position, throttle‑plate angle, and airflow. A failure triggers "Failure Mode Effects Management" (FMEM), reducing speed but keeping steering and brakes functional. (NHTSA)

• Rough or high idle
• Engine stalls at stoplights
• "Limp‑home" mode with max 35 mph
• Codes P2111 (plate stuck open) or P2112/P2119 (plate stuck closed/range) showing on an OBD‑II scanner (Kbb.com, JustAnswer)
• Wrench or MIL lamp plus reduced throttle response
• Surging, uneven acceleration

Ford issued Customer Satisfaction Program 13N03 extending throttle‑body coverage to 10 years/150,000 miles after contamination was linked to sudden power loss.
A U.S. NHTSA review (DP12‑006) examined failures on 2005‑2012 Escape/Mariner SUVs and confirmed ETC faults could trigger limp‑home but still allow safe steering and braking. (NHTSA)

1. Pull OBD‑II codes-look for P2100‑P2119 family. (Kbb.com)
2. Watch live data: throttle‑position should sweep smoothly from ~13 % (closed) to ~85 % (wide open).
3. Inspect for carbon or oily sludge on the butterfly plate.
4. Check harness plugs for moisture or bent pins.
5. Verify idle air passages are clear.

Tip: A stuck‑open plate raises idle; a stuck‑closed plate causes stalling. Knowing which code you have guides next steps.

A mild cleaning every 60-100 k miles helps prevent issues. Use a throttle‑body spray, a soft toothbrush, and eye protection. Berryman Products' guide lists simple steps and warns against scraping the coating.
Benefits include smoother acceleration and better gas mileage.

If cleaning fails or you have internal motor faults, replacement is next. RepairPal pegs average U.S. cost at $555‑$756 (parts $433‑$577; labor $122‑$179). (RepairPal.com)
After installation, turn the key ON (engine OFF) for 10 sec, switch OFF 10 sec, then start and idle 3 min-this lets the PCM relearn the closed‑throttle position (a self‑calibration noted in Ford service bulletins). (NHTSA)

• 2005‑2008 models use a cable‑actuated body on 2.3 L (L3) engines.
• 2009‑2011 (2.5 L Duratec & 3.0 L V6) switched to full electronic throttle assemblies-these are not interchangeable with earlier units.
• Hybrid Mariners share the same housing as equivalent Escape hybrids, but calibration differs, so always match part numbers.

Upgrading to a port‑matched, smoother‑bore throttle body on a Mariner V6 can add a few horsepower and slightly raise airflow, as off‑road tests have shown. (MotorTrend)
However, gains are modest unless paired with intake and exhaust mods, and an engine tune is recommended.

A clean, correctly sized throttle plate helps the PCM keep the ideal 14.7:1 air/fuel ratio for cruising. (A rich mix wastes fuel; a lean mix hurts power.) (MotorTrend)
Drivers see 1-3 mpg improvements after restoring proper airflow. Regular tire pressure checks, clean oxygen sensors, and light vehicle weight magnify the benefit. (MotorTrend)

• Scan, clean, re‑learn first-many "bad" units just need a deep cleaning.
• Keep battery voltage healthy; low voltage can mimic throttle faults.
• Use the correct gasket and never overtighten bolts to avoid vacuum leaks.
• Check Ford TSBs for calibration updates-the dealer can flash newer software that refines idle quality.

Related resources for deeper reading

• NHTSA electronic throttle investigation summary (NHTSA)
• RepairPal cost estimator
• HowStuffWorks explanation of throttle control

Mercury Mariner throttle body, air‑intake valve, and ETC throttle assembly. Happy writing!