It’s a good idea to clean up the throttle body every so often, as the oil vapor in the PCV system condenses on the cooler walls of the intake. This leaves a nice oily scum, which could potentially cause problem with the throttle butterfly valve.
1) Remove the air filter & AFM. See the intake page for assistance.
2) Remove the Throttle Body by removing the below circled hoses, bolts, etc. Consult the BGB or Haynes for more details:
a) Green – Remove the VTV and it’s hoses, take note of which way the VTV is situated, black side to the rear of the carb) Red – Air hose and clampc) Yellow – 4 coolant hosesd) Orange – There’s 2 coolant hoses w/ clamps here behind the VTV. Both are full of coolant, so be sure to be ready for some spillage as you remove them.e) Purple – Remove the throttle spring and the adjustment rod. The rod is removed by just prying and spinning it out.f) Blue – Now you can remove the two 12mm nuts and two 12mm bolts that hold the throttle body in place. There’s also a 12mm bolt that connects the yellow-circled hoses to the TB, which you cannot see in this pic. You will need to remove it too.
3) Here’s the the intake with the TB removed. You can see the oily residue. Clean up inside as far as you can reach, but don’t drop anything down in there.
4) Just some pics of the TB cleaned up. It will be just as dirty as the intake. So, take some carb cleaner to it and clean it up nicely. But! before you do this remove the TPS, as getting brake cleaner on it will likely damage it. Just remove the 2 screws and pull it out. You will need to readjust it when putting it back on the car. Also, make sure to clean up the old gasket on the TB and the intake manifold with a razor blade, making sure not to scratch or gouge the surfaces.
Just a pic of the TPS removed:
5) When replacing the TPS it’s a good idea to replace the screws with some allen wrench type bolts. This way the TPS is easier to get to to adjust while the TB is on the car. The name/size of the bolts to get from your local Lowes/Home Depot is “4mm x 12mm cap screw socket”. I also used two 4mm washers.
5) Now you need to adjust the TPS. For help with that, go here.
6) Installation of the TB is opposite of removal. Use some Permatex RTV for the gasket between the TB and intake manifold, or purchase a new gasket from Toyota. Also, make sure to burp the coolant system once you get everything back together. You also may need to adjust the idle speed screw that is on the TB.