To get the internal combustion engine all fired up, it needs just the right supply of oxygen aside from ample amount of fuel and a well-timed spark. The throttle body, which is essentially an air valve, feeds air into the engine whenever you step on the gas pedal. When the accelerator is pressed, the throttle plate is opened by the cable. The plate that covers the mouth of the throttle body opens wider as you press harder on the gas pedal, letting in more air into the combustion chambers. Throttle bodies that are clean and properly maintained will keep idles smoother and throttle response a whole lot better. If they're clogged with dirt, engine efficiency and vehicle performance may suffer.
Tips on checking for a dirty throttle body
- Watch out for erratic idles and sputters.
- Note how your vehicle is accelerating.if acceleration is slow or uneven.
- Look for that black, tar-like residue in the body.
- Check if the vehicle's gas mileage is dropping.
Dirt and clogging may cause engine sputters, erratic idles, uneven and slow acceleration, and decreased gas mileage. If you notice or encounter any of these symptoms while driving, check for dirt or residue in the body. Clean this off to restore good throttle response and engine performance.
How to clean a throttle body
Dirt, sludge, and carbon buildup on throttle bodies should be cleaned off. For this service, throttle bodies have to be removed, cleaned, and reinstalled. Here's how it's done:
Step 1: Relieve some fuel system pressure as you pop the hood and get ready to remove and clean the unit. After this, the black negative cable should be disconnected from the battery terminal. A manual will come handy with instructions for relieving pressure and for locating parts.
Step 2: Remove the air cleaner assembly and then pull out the cable/s linked to the throttle lever. You also have to disengage the electrical connectors from sensors, idle control motor unit, and valves. Vacuum hoses must also be disconnected. Keep in mind how the cables, connectors, hoses, and other units are connected so you'll know what to do when it's time to reinstall them.
Step 3: Unplug the inlet and return fuel lines from the body. You then have to undo the bolts or nuts that secure the unit to the intake manifold. You can either use a wrench or a ratchet and socket for this task. Once the unit is free from bolts or nuts that hold it in place, you can pull this out. The plastic, rubber, and electrical parts must be unplugged. Just remember how they're assembled so you can put them back easily.
Step 4: Clean the throttle body unit using a special cleaner. Be sure to follow the instructions from the manufacturer. Once the unit has been clean, you have to check for broken gaskets, seals, and other components. Replace these parts before you go on reassembling the unit in place. Use the ID number that's stamped on the unit as a guide if you'll be buying new gaskets, seals, and other attachments to the body.
Step 5: Keep the mating surface of the intake manifold clean from the gasket material. You can remove the gasket material on the surface with a scraper, lacquer thinner, and a clean rag. Once clean, you can move on to installing the unit on the intake manifold. A new base plate gasket must be used. The mounting bolts should also be tightened according to specifications.
Step 6: Reconnect and reinstall cables, lines, connectors, hoses, and parts that were unplugged or removed. After putting everything back in place, plug in the black, negative cable to the battery terminal. Drive around to test the service throttle body and check if the idle and acceleration have improved.