What Is a Throttle Body?

The throttle body of your vehicle is basically a butterfly valve. The throttle body’s core function is to regulate and control the amount of air allowed to enter the engine.

There is only one throttle body in most vehicles, with a rare exception of special, larger vehicles. The function of the throttle body is also dependent on other parts, such as the air filter.

Bad Throttle Body Symptoms：

Common symptoms of a failed throttle body include poor performance, rough idle, stalling and an illuminated check engine light.

Part 1: Removing the throttle body

Materials Needed: Gasket Scraper, Plier Assortment, Screwdriver Assortment, Socket Set, Wrench Set

Step 1: Locate the throttle body. The throttle body is mounted between the airbox and the intake manifold.

Step 2: Disconnect the negative battery cable. Disconnect the negative battery cable and set it aside.

Step 3: Remove the air intake tube. Loosen the clamps on each end of the air intake tube with a screwdriver. Then slide the air intake tube off.

Note: In some cases, the air intake tube may also have hoses and electrical connectors attached to it that must also be removed.

Step 4: Remove the throttle controller electrical connector(s). Remove the throttle controller electrical connector(s) by pushing down on the tab and pulling it off. In some cases, the connectors may also have tabs that need to be pried back using a small flathead screwdriver.

Step 5: Remove the throttle body bolts. Using a ratchet, remove the bolts holding the throttle body to the intake manifold.

Step 6: Remove the throttle body.

Step 7: Remove the throttle body gasket. Carefully remove the throttle body gasket by using a small screwdriver to pry it off. Clean any remaining gasket material by using brake cleaner applied to a rag.

Part 2 : Installing the new throttle body

Step 1: Install the new throttle body gasket. And mount the new throttle body in position.

Step 2: Install the throttle body bolts. Install the throttle body bolts by hand one at at time. Then tighten them down using a ratchet.

Step 3: Reinstall the electrical connector(s). Reinstall the connectors in the same way that you removed them.

Step 4: Reinstall the air intake tube. Slide the tube into place and tighten down the clamps using a screwdriver.

Step 5: Reconnect the negative battery cable. Reconnect the negative battery cable and tighten it down.

Finally, the engine is started, brought to normal operating temperature, and idle speed is checked. The car is road tested to ensure normal operation and no illumination of warning or service lights.

When replacing the throttle body keep in mind:

(1) Many modern throttle bodies have spring loaded sensors and plastic gears that are not intended to be manipulated directly during any diagnostics or inspections. These components are controlled electronically or generate signals. It is best to let a mechanic use approved tests to diagnose the problem.

(2) Wiring faults, bad grounds, or bad terminal connections can make it appear as though an electronically controlled throttle has failed. A mechanic will always rule out all other causes before replacing the throttle body.

For Ford Idle Relearn Procedure

Please note that there are a few different procedures depending models and years. The procedure below is common in most the Ford vehicles.Refer to your owner’s manual for the specific idle relearn procedure of your vehicle.

IMPORTANT

After the replacement of the electronic throttle body, the engine idle speed may fluctuate, cause the engine to stall or even turn on the check engine light.

IDLE LEARN

Perform the following relearn procedure for the on-board computer to adjust to the new idle position on the electronic throttle body.

1. Start and run the engine in PARK for 3 minutes.

2. Turn the engine OFF for a minimum of 60 seconds.

3. Start the engine and run for another 3 minutes.

4. Engine should idle normally after 3 minutes.

After having performed the relearn procedure and the engine still does not run within normal idle speed, it will be necessary to drive the vehicle above 45 mph (70 Km/h) including several decelerations. Also ensure that after driving the vehicle, let the engine idle for a minimum of 5 minutes. If the engine has returned to normal idle speed, the relearn procedure is completed. If the idle speed is still erratic or incorrect, restart idle relearn procedure.

Does my car need Idle Relearn?

In general, the procedure of idle relearn is necessary on vehicles with electronic throttle body (=ETB aka DBW Drive-By-Wire).

Why does Idle Relearn need?

Many newer vehicles use an electronic throttle body which contains a throttle plate, motor, and sensors. They are responsible for regulating all air flow into the engine, including the air flow for maintaining idle speed. When idling, the vehicles computer sends a signal to the throttle body and controls the throttle plate to adjust the idle speed depending on the engine temperature and whether AC is on or off. When the computer loses the connection to the throttle body, it loses the position of the throttle plate. Thus, the vehicle computer needs to relearn the throttle plate after losing connection to it.

How can you get the procedure of idle relearn?

Unfortunately, not all repair manuals have the information about idle relearn. And you may or may not find it in the owner’s manuals. So where can you find it? Go online, search "idle relearn + make, model, and year of your vehicle, " and you may get results. If not, search "idle relearn + make" only. The procedure may be the same among all vehicles from the same manufacturer.

What will a new throttle body do?

In addition to increasing acceleration performance, larger throttle bodies can also boost overall horsepower. This gives the engine increased power and torque, which may be helpful in situations such as towing. Commonly, adding an aftermarket throttle body can increase engine power by 15 hp to 25 hp.