How to Clean an Air/Fuel Intake System

Improve engine response and idle in 30 minutes

Complete a 30-minute fuel system tune-up and improve your car engine's response time and idling. The kit only costs $35.

By the DIY experts of The Family Handyman Magazine

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Clean the air/intake fuel system

Do you get a crummy idle or poor engine response when you put the pedal to the metal? You may have soot and carbon buildup on the valves, intake manifold and throttle body assembly, as well as clogged fuel injectors. Shops charge $80 and up to perform a fuel induction cleaning service. But you can do the same thing in about 30 minutes with the 3M No. 08963 Do-It-Yourself Fuel System Tune-Up Kit; about $35. The kit is available through our affiliation with Watch the instructional DVD. Then grab the kit, a screwdriver, goggles and rags and you’re ready to bust crud.

Start by disconnecting the air duct (engine off) at the throttle body (Photo 1). Then position the U-shaped injection tube at 12 o’clock inside the throttle body (Photo 2). Have a friend start the engine and press on the gas pedal to raise the engine speed about 500 rpm above normal. Press the spray valve on the aerosol can until it locks open. Then run the engine at the higher speed until the can is empty. Shut off the engine and remove the injection tube.

With the air duct still removed, spray the front side of the throttle plate with throttle plate cleaner (Photo 3). Next, turn the key to the run position (don’t start the engine!) and have your friend press the gas pedal to the floor. Spray the back of the throttle plate and any carbon buildup you see in the throttle area. Turn the key to “off” and reinstall the air duct.

Finally, dump the bottle of fuel system cleaner into a full tank of gas (or 1 oz. of cleaner to 1 gallon of gas) and drive the vehicle for 15 minutes.

Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • 4-in-1 screwdriver
  • Safety glasses

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

  • Fuel system tune-up kit

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