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Throttle Body Cleaning - 1990-1996 Q45

No guarantees are made on the results, and anything you do yourself is at your own risk.

Throttle Body Cleaning
By Jesda Gulati

Credit to "AZHitman", Jeff Williams, Wes, and "Daedalus" on NICO for this information.
See the original NICO thread.

Occasionally, rough idle and acceleration hiccups can be caused by a dirty throttle body. Under acceleration, the throttle plate opens and then closes at idle. Carbon deposits and dirt can prevent the plate from properly opening and closing. These directions will assist you in a partial cleaning of the throttle body. This omits the step of removing the throttle body itself for completely cleaning. If you decide to remove the entire throttle body, you will need to purchase a throttle body gasket.

You will need to purchase one can of Valvoline Carb, Choke and Throttle Body Cleaner, for approximately $2.50-$3.50 at Autozone or Advance Auto Parts. Some have said that any can of carb cleaner is a sufficient substitute. You will also need an 8mm ratchet or wrench and a pair of pliers.

The throttle body is located at the end of the black plastic air duct, just to the right of the plenum and left of the power steering fluid reservoir. If your Q45 has traction control, it may look a bit different but relatively the same.

First, loosen the clamp that holds the air duct to the throttle body.
Second, pinch (with a pair of pliers) and slide back the two hose clamps pointed out in the photo above.

Once the two hose clamps are moved, you can (preferably by hand) slide the hose out.

Gently pull out and lift the air duct, and sit it on top of the throttle body as displayed in the photo above. 

This is a close-up of what it looks like inside the throttle body after 188,500 miles. Notice the build-up around the edges that often affects idling and acceleration.

Below the air duct is another hose with the same kind of clamp, which can easily be pinched and slid backward with a set of pliers. Once the clamp is moved, gently slide off the hose.
Next, slowly lift the air duct and rotate it counter-clockwise to move it out of the way.

Take the can of cleaner and generously spray all around the inside. Keep spraying until the liquid that drains out is clear.
Next, rotate the throttle arm on the right (its connected to a throttle cable and a bunch of springs) and continue to spray inside. You will see more dirt and debris coming out.

After you finish, reassemble everything and be careful not to overtighten the 8mm bolt on the air duct clamp.

Most prefer to wait a half hour before starting the vehicle. You can, however, start it immediately. It will not start on the first couple tries, but eventually it will come to life. Idle for a bit and hit the gas a couple times, then go for a drive. Preferably, get on a highway ramp with the gas floored all the way to 70mph, then let off. You should notice easier shifts, smoother acceleration, and smoother idle.

This web site is the intellectual property of Jesda Gulati and Wes Stinson.