97VetteDan

I plan on doing the following TB cleaning process on my 1997 Corvette tomorrow:

Disconnect the red positive terminal on the battery before you do anything else. Loosen the screw clamp that holds the air bridge to the throttle body. It's easiest to remove the entire intake duct from the car. This means loosening the clamp from the other end as well. Unplug the wire that connects to the throttle position sensor (TPS), located on the passenger side of the throttle body. Be careful when you disconnect the electrical connectors that you don't break the locking tabs. Since we're also going to disconnect a coolant hose, make sure this plug is positioned so it won't get wet from the coolant. Now unplug the wiring connector that goes to the electric motor on the driver's side of the throttle body. Use a small screwdriver to depress the connector tab, and gently wiggle the connector loose. Using needle- nose pliers, compress the small gray spring clamp that holds the coolant return line in place. Move the clamp approximately 2 inches down the line, but don't remove the hose yet. Remove the coolant overflow tank cap, located on the passenger-side fender well with a yellow sticker on the cap. Remove the cap very slowly, allowing the pressure to escape the tank. Leave the cap off for now. Find a 'A-inch rubber cap (vacuum line caps are good for this), and remove the rubber hose from the end of the hard line. Place the rubber cap over the end of the line to prevent spillage. Keep the rubber hose in the upright position and place the hose against the air conditioning lines on the passenger-side fender well. Keep it pointed up to prevent spillage. Now remove the PCV return line from the throttle body. Place it aside and out of the way. Use a 10-millimeter socket to remove the three bolts that hold the throttle body to the intake manifold. Gently move the throttle body forward and let it rest. Place the bolts on the windshield tray so you can find them later. Now comes the hard part. Use the needle-nose pliers to compress the gray spring clamp that holds the short rubber hose from the coolant lines at the heads to the throttle body.
Work this clamp down the rubber hose toward the throttle body, and remove the rubber hose from the hard line at the heads. There shouldn't be any pressure in the cooling system; very little, if any, coolant should run out. Take the throttle body with the attached rubber hose over to your workbench. Use pliers to compress the spring clamp holding the rubber hose to the throttle body's hard line. Remove the rubber hose from the throttle body and install it on the new throttle body (or your freshly cleaned one). Take another minute to inspect the clean, or new, throttle body. Make sure nothing obstructs the throttle blade and that the throttle plate moves freely. Make sure the mounting face for the throttle body gasket is clean and totally smooth. Place the throttle body in the engine compartment and slide the rubber hose back onto the hard line from the heads. This is tricky and may get frustrating; just make sure you scat the hose all the way up the hard line. Use the pliers to compress the spring clamp and slide this clamp back up the hose. Make sure it's actually clamping the hose to the hard line. Replace the three bolts that hold the throttlebody to the intake manifold. Get each bolt started before tightening it down to 9 ft-lb. Remember, the throttle body is aluminum, but the intake manifold that you are bolting it to is composite plastic. You can easily break the intake plenum if you over tighten the bolts. Reconnect the PCV line to its fitting on the throttle body. Now carefully slip the return hose to the radiator back onto its fitting. Make certain that this hose is seated all the way up the hard line, and use the pliers to reseat the spring clamp properly. Reconnect the TPS sensor connector on the passenger side. Make sure that the clip snaps into place properly and is locked in place. Reconnect the throttle wire connector to the electric motor on the driver's side. Again, make sure that the clip snaps into place. Replace the coolant overflow tank cap. Replace the air intake bridge and check that it's seated firmly. Reconnect the red positive battery terminal. Now relax and look at all the coolant lines, electrical connectors, rubber hoses, and bolts. Take your time and make certain that everything is back in place and everything is firmly fastened together. Start the car and inspect the coolant lines for any leaks. If there's leaking, shut the car off and correct the problem. Check the coolant level and add coolant/water if necessary. Drive the car around the block or up and down the street a few times, just to make sure no codes have been thrown with the addition of the new or cleaned throttle body.

Should I use a rag or a thoothbrush while cleaning?

WICKEDFRC

Suggest a lint free rag. Unless of course, there is a prank you wish to play on someone in the house, use their toothbrush, not yours.

RonSSNova

3m heavy duty brake cleaner. Just keep it off of the electronic parts.
If you need a brush, and toof brush is just fine.