The most common cause of stalling in your Ford Focus SE relates to control of the air entering the engine. The air entering your engine is measured by the MAF (Mass Airflow) sensor and the onboard computer calculates the proper amount of fuel for that volume of air, as well as the position of the Idle Air Control valve for the proper idle speed. These calculations rely on the gap between the throttle body and the throttle blade. When this gap is eliminated by carbon deposits or the MAF sensor becomes contaminated, the computer can no longer control idle speed.
Things You'll Need
- Screwdriver set
- Torx driver set
- Spray parts cleaner
- Shop towels
- Scan tool
Start the engine and run it until the temperature gauge in the instrument cluster reads in the normal range. Turn the engine off.
Remove the rubber air duct connecting the throttle body and MAF sensor, using a screwdriver or 8-mm socket and ratchet to loosen the large hose clamps. Unplug the vent tube from its rubber grommet in the duct and lay the duct aside.
Clean the throttle body by spraying a liberal amount of the throttle body cleaner into the throttle body around the throttle blade. Allow the cleaner to sit for a few minutes to soften the carbon deposits. Have a helper hold the gas pedal to the floor while you wipe the residue from the throttle body and blade. Repeat this until the throttle is clean.
Turn the ignition key off. Unplug the electrical connector from the MAF sensor attached to the side of the air filter housing. Remove the two small torx-head screws, that attach the sensor to the sensor housing, using a T-10 size torx driver. Carefully slide the sensor out of the housing.
Spray the exposed sensor wires and sensor disc on the end of the sensor that fits inside the housing, using MAF cleaner. Allow it to dry completely before reinstalling the sensor into the housing. Reinstall the rubber duct and tighten the hose clamps securely. Test drive the Focus to verify that it no longer stalls.
Tips & Warnings
- Use the parts cleaner spray sparingly to avoid fouling a spark plug.
- Excessive amounts of liquid cleaner may settle in the intake manifold and damage the engine upon start-up.
- Wear safety glasses and work gloves when working around a running engine to prevent serious injuries.
- "Chilton 2000-05 Ford Focus Repair Manual"; Jay Storer; 2005
Ford Focus Wagon Problems
The Focus is a compact car manufactured by American automaker Ford and sold in many different markets around the world, The Focus...
Ford Focus Engine Problems
Ford introduced its compact Focus in 1999, and the car immediately climbed its way to the top of the compact car ladder...
How to Check for Fuel Delivery in a Ford Focus
The Ford Focus is a compact car that debuted in North America in 2000 as a sedan, three-door and five-door hatchbacks and...
How to Troubleshoot the Electrical System in a Ford Focus
The Ford Focus appeals to people who like what "Ford" stands for, but who still want an economy car to combat rising...
How to Replace the Throttle Body in a Ford Focus
The ford Focus made it debut in 2000. It boasts abundant character and thoughtful styling along with several body options, all having...
How to Diagnose a Ford Focus That Will Not Start
A no-start problem in your vehicle may be caused by one or more systems in your car. It could be as simple...
How to Clean a Ford Focus IAC Valve
The Engine Management System (EMS) on your Ford Focus uses the Idle Air Control (IAC) valve to adjust idle speed. This valve...
How to Replace a 2001 Ford Focus Fuel Filter
Although not a part of regular vehicle maintenance, there will come a time when you'll need to replace the fuel filter on...
Problem With a Ford Truck Stalling & Idling Rough
When a vehicle idles poorly or stalls out, it can be dangerous for the driver and occupants. There are a number of...
Throttle Body Injection Troubleshooting
The throttle body in a car provides the control of air and fuel injection so that the system runs efficiently and does...
Problems With the 2000 Ford Focus
Throughout the 2000s, the Ford Focus was the subject of several recalls. According to the Insideline website, there were eight recalls during...
Ford Faulty Fuel Pressure Regulator Symptoms
The fuel pressure regulator controls the fuel pressure in your Ford’s fuel system, maintaining the proper pressure needed for your vehicle to...
Problems With Ford Engines Idling
All engines at one time or another will have idle problems; Ford engines can have idle stumbling, surges and stall-outs, no matter...
Problems With the Ford Focus
The Ford Focus is a sedan or hatchback made by the Ford Motor Company that is known for having good gas mileage,...
2002 Focus Transmission Problems
Seven recalls have been issued for the 2002 Ford Focus, according to carcomplaints.com, but none of these recalls has dealt with the...
Problems with Ford IAC Valves
The idle air-control valve is designed to regulate the idle on your Ford car or truck. A malfunctioning idle air-control valve can...