C4 Corvette running a little rough? Feel like you might not be getting all the power out of your car like you should? Your throttle body could be dirty and need a little cleaning. This is an easy improvement to your Corvette to help it run better. Plus it’s a good idea to check the easy things first before diving into more complex repairs

Tools you will need

• A new throttle body gasket kit. You gaskets might be OK but a new set is relatively inexpensive and worth changing out while you are cleaning things up.
• Throttle body cleaner. Do not use carburetor cleaner.
• Toothbrush. I used the one I was using and replaced it with a new one for the bathroom.
• Some sort of bowl, rags and gloves if you prefer. Things will probably get dirty.
• Digital multimeter. You need this if you’re checking your TPS sensor. Its a good idea to make sure you have the correct voltage.

Removing the throttle body

Remove the air duct in front of the throttle body. Will the engine off, open the throttle body by hand and feel behind the butterfly blades. It is most likely super dirty behind there. That’s what you need to clean off. I’ve done the same thing with the throttle body on my Ram 1500. Those things get dirty and need to be cleaned periodically.

Remove the 3 pin connector from the throttle body position sensor and remove all the other connections to the throttle body. There may be a little water that might spill. Also, remove the IAC connector, it has 4 wires, and it’s somewhat difficult to get to.

It’s now time to release the throttle cables. They are slightly different for a manual vs automatic. The cables are held on with clips nicknamed Jesus clips. If you lose them words like Jesus or worse, come out of your mouth. Slide a screwdriver under it and be very careful you don’t flick them or lose them down in the engine bay.

With the clips removed you and now release the cables. Remove the 4 long bolts holding the throttle body to the plenum. If you purchased new gaskets (a good idea) you can just ply off the old ones without worrying about damaging them. If you want to reuse them be careful not to damage them here.

Underneath the throttle body is vacuum tube with a rubber elbow that needs to be removed. These hoses get brittle and break easily so be careful. It’s a good idea to replace these hoses with you’re cleaning the throttle body. You can get replacement hoses from any auto parts store or on line.

Cleaning the throttle body

Take the throttle body you just removed and put it in the bowl you got at the start. Spray the throttle body wiht the throttle body cleaner and scrub vigorously with your old toothbrush. Clean until you get all the dark dirty crap off your throttle body.

Now remove the IAC valve, watch for the gasket. Clean the spring and pintle and inside the getting the seating area. Be sure the small hole from the throttle to the IAC is clear. After cleaning, it, spray the spring and pintle with WD-40 and replace the IAC valve back on the throttle body.

One last look and cleaner spray to make sure the throttle body is cleaned as well as possible. It’s also a good idea to clean into the plenum while the throttle body is off.

Put it all back together

After letting everything dry it’s time to put everything back together. Be sure the new or reused gasket between the plenum is put on correctly. Reattach everything the was removed including the tube under the throttle body, and the throttle cables.

It’s a good idea to check the throttle body sensor at this point. The correct setting is 0.54 volts I should have instructions how to do this on this page soon.

Conclusion

I hope this helps you clean up your throttle body and helps your car run better. This is a relativily easy repair but can pay dividends in how your Corvette runs. When working on these old C4 Corvettes its best to try the easy, quick and inexpensive repairs first. Its possible to spend a lot of money chancing down a problem and still not find it. Good luck in your repairs.

Got a comment or question about this post? Shoot me a comment below, I will be sure to get back to you soon.