Fox Body Engine Bay Diagram (1986-1993)

Created by Jay Walling
Date Created: 9/7/2018
Last Updated: 12/22/2023

LMR breaks down each part in your Fox Body's engine bay with this easy to use infographic. Find out which parts you may be missing and pick up the direct replacement parts you need.

Viewing this install and using the information shared is subject to the terms set forth here - View the LMR Install Instructions Disclaimer.
Fox Body Engine Bay Diagram  - Fox Body Engine Bay Diagram
  1. Upper Intake Plenum - The upper intake plenum on your Fox Body Mustang is usually the first thing that someone sees in your engine bay. The factory plenum looks great, but most opt for a performance intake that allows your engine to make more horsepower while dressing up your engine bay.
  2. Distributor - The distributor in your Mustang’s engine passes electrical current from the coil to each spark plug in a rotational manner. The distributor drive gear is driven by the camshaft which determines the speed that the electricity is distributed.
  3. Mass Air Flow Sensor - Your Mustang’s mass air flow sensor is a sensor mounted in the intake tubing used to measure the mass flow rate of the air entering into your engine. It relays this information to the ECU to disperse the correct fuel for optimal performance.
  4. Air Filter Housing - If your Fox Body is still relatively stock, you most likely still have the factory air filter housing installed. It will be a black box located in the bottom left hand of your engine bay and connects to your air intake tubing. It houses an air filter to filter incoming air of any contaminants.
  5. Alternator - The alternator in your Mustang helps to charge the battery when your car is running. While the engine is operating, the serpentine belt is spinning which turns a pulley on the alternator. This generates power that is sent to the battery to keep it fully charged.
  6. Belt Tensioner - Speaking of the serpentine belt, the reason why the belt stays pressed firmly against the pulleys is the utilization of a belt tensioner. The belt tensioner mounts to your engine and is equipped with an arm and free spinning pulley that creates tension on the belt to keep it from becoming loose and slipping.
  7. Overflow Tank - The overflow tank is a plastic tank that collects any coolant that has expanded in the radiator and recycles it back into the coolant system after it has lost enough heat.
  8. Radiator Cap - While it may seem like just a metal cap, the radiator cap has a special purpose. The radiator cap creates pressure to keep your cooling system at a higher PSI which increases your coolant’s boiling point. This helps your coolant absorb more heat from your engine.
  9. Battery - The battery is one of the single most important parts of your engine bay. A car battery provides power to your motor that enables the motor to function. With a dead battery, you will not be able to start your car nor use any of it’s electrical functions.
  10. Power Steering Pump - The power steering pump works in conjunction with your steering rack to make turning your wheels as easy as possible. The pump uses fluid to create pressure to help move the wheels with ease.
  11. Air Conditioning Compressor (If Equipped) - The air conditioning compressor works as a pump to move refrigerant through your A/C system to create cold air for your Mustang’s cabin.
  12. Brake Master Cylinder & Booster - The heart of your brake system, the brake master cylinder and booster, it the reason your brakes operate so easily. The booster and master cylinder work in conjunction using vacuum and a system of brake lines to distribute brake fluid to each caliber/drum.
  13. Windshield Wiper Motor - At the back of your engine bay, mounted on the firewall, is the windshield wiper motor. This motor powers your windshield wipers. From the factory, this is neatly covered with a plastic cover, but these are usually lost or broken over time. Luckily LMR has a replacement Fox Body windshield wiper motor cover to make the fix.
  14. Hood Ground Strap - The ground strap that connects from your hood to the chassis helps to ground your underhood light. This strap is near the back of your engine bay on the passenger side.
  15. 10 Pin Connector - Commonly referred to as the Fox Body salt and pepper shakers, these connectors serve as the main engine to body wiring harness junctions. These commonly become corroded or the bracket breaks. Luckily, LMR has you covered with a new Fox Body 10 pin connector mounting bracket.
  16. EGR Spacer - Your Fox Body's EGR spacer is a vital part to your 5.0 exhaust gas recirculation system. It also provides a mounting point for your throttle cable.
  17. EGR Vacuum Regulator Solenoid - Another important part of your EGR system is the vacuum control solenoid. This part is operated by the PCM and allows vacuum to the EGR valve.
  18. Idle Air Control Motor - This IAC is a solenoid that bolts to the throttle body and controls idle changes caused by engine loads. When your IAC is going out, you may experience surges or poor idle quality.
  19. Thermactor Air Diverter Solenoid - The thermactor air diverter solenoid, commonly referred to as TAD, is a component of your Fox Body's vacuum system.
  20. Air Inlet Hose - The air inlet hose is your factory intake tubing that delivers air from the air box to your engine and throttle body.
  21. Oil Filler Cap - The oil filler cap is the cap to the oil filler neck where the oil is filled on your engine.
  22. Mass Air Flow Meter - The mass air flow meter is a meter that sits in your intake tubing and reads the amount of air coming into your engine to adjust for the correct fuel.
  23. Radiator - Your Fox Body radiator is the main component of your cooling system. A radiator cools hot coolant after it has traveled through your engine using air coming through the front bumper.
  24. Spout Check Connector - The purpose of the spout connector is to complete the circuit to the distributor to allow the PCM to have timing control. You remove the spout connector to disable PCM timing control so you can accurately set your base timing by twisting the distributor and using a timing light.
  25. Engine Coolant Temperature Sensor - A fundamental part of regulating air/fuel ratio, ignition timing, and EGR flow. A malfunctioning Mustang coolant temperature sensor can provide false information to your Mustang's computer that could cause anything from erratic idle to catastrophic engine failure on your Mustang Engine!
  26. Fuel Injectors - Fuel injectors are one of the main reasons your fuel gets to your engine correctly. They disperse fuel in a fine mist in a specific volume to deliver just the right amount of fuel for your engine to operate at it's best potential.
  27. Water Pump, Fan & Fan Clutch - The water pump, fan, and fan clutch are parts of your coolant system that help cool and move coolant throughout your engine.
  28. Center Line Crash Sensor - The center line crash sensor is located at the front of your Fox Body to detect front end collisions for air bag equipped cars.
  29. Power Steering Fluid Resevoir - The power steering fluid reservoir holds the fluid that powers the steering system in your Fox Body.
  30. Ignition Coil - Your ignition coil on your Fox Body supplies voltage to your distributor which transfers the electricity to your spark plugs. It is easy to find by tracing the single spark plug wire from the distributor.
  31. Starter Relay - Commonly known as a starter solenoid, the start relay switches a large electrical current to the starter to start your engine.
  32. Engine Oil Dipstick - Providing you an easy way to check your oil levels, the engine oil dipstick has markings on the very bottom to show you exactly how much oil you have in your motor.
  33. Front Strut Insulator & Camber Adjustment Plate - The front strut insulator and camber adjustment plate rest on top of the strut and strut tower and are used in dampening and adjusting your suspension.
  34. VIP Test Connectors - Also referred to as the EEC/OB1 tester, this connector allows you to hook up the Ford Star tester tool to your Mustang to read codes.
  35. Barometer Absolute Pressure Sensor - To help manage a proper air to fuel ratio, your Mustang's BAP barometer absolute pressure sensor, has to function properly
  36. EGR Valve & EGR Position Sensor - Your EGR valve helps reduce emissions by rerouting exhaust gases back into the combustion chamber.
  37. Crankcase Ventilation Tube - The crankcase ventilation tube allows blow-by gases to escape from the crankcase in a controlled manner.
  38. Vacuum Distribution Tree - The vacuum distribution tree does exactly what it was named after, distributed vacuum to all of the vacuum controlled components on your engine.
  39. Wiring Harness - This wiring harness is the main engine harness that runs along the back side of your motor, near the firewall.
  40. Thermactor Air Bypass Solenoid - The thermactor air bypass solenoid, commonly referred to as TAB, is a component of your Fox Body's vacuum system.
  41. Vacuum Storage Canister - This canister allows your motor to store vacuum to keep your engine running smoothly at wide open throttle.
  42. WOT Cutout Relay - The relay disengages the air condition compressor clutch when at wide open throttle.
  43. Fuel Pump Relay - The fuel pump relay helps send a signal to your fuel pump to turn on when your ignition is turned on.
  44. Air Silencer - The air silencer is located in the fender and keeps the noise levels down from incoming air.
  45. Air Coniditioner Condenser Connections - These connectors connect the air conditioning lines to the a/c condenser.
  46. AC Accumulator - The accumulator is similar to a filter for your a/c system that removes foreing materials from your lines.
  47. Thermactor Air Pump - A thermactor air pump delivers fresh air to your catalytic converter or exhaust system.
  48. EGR Coolant Hoses - These hoses carry coolant to your EGR spacer.
  49. Throttle Position Sensor - The TPS is a sensor that measures the position of the throttle.
  50. AC Low Pressure Switch - This switch monitors the pressure of the a/c system to ensure that your a/c compressor does not operate in damaging conditions.
  51. Vacuum Check Valve - This valve directs the flow of air to create a vacuum for various components.
  52. Fuel Pressure Regulator - The fuel pressure regulator helps to control pressure in your fuel system to ensure your motor gets the correct amount of fuel.
  53. Positive Crankcase Ventilation Valve - Commonly referred to as the PCV valve, this valve helps regulate crankcase pressure.
  54. Air Charge Temperature Sensor - This sensor works in conjunction with your computer to adjust fuel for optimal a/f ratios.

  55. Source:Ford Motor Company and

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About the Author

Jay has written content for Late Model Restoration for over 10 years, producing over 120 articles. Jay has an extensive 25-plus-year background in automotive and is a certified Ford Technician. Read more...