Hello!

I'm posting this for anyone who has already or is thinking about cleaning their throttle body. I'll be going over my experience to help anyone looking for it like I was.

Firstly, I have a 2005 350z 6-speed. I had purchased the car several months ago and have been doing some maintenance while trying to better understand the car and make it a little more of my own. Besides serious cleaning, oil changes, and just tightening things up, cleaning the throttle body was my first somewhat real en devour into the car. I apologize ahead of time for any misunderstandings that may happen. So here I go...

I started off the cleaning by disconnecting the battery and removing the intake hose and throttle body completely. I used crc throttle body cleaner, several rags, and some q-tips to clean the seriously dirty throttle body. I decided to move the butterfly valve as it was my goal the clean it as well as possible. When I was finished I reassembled and reconnected the battery no problem.

Upon starting the car I experienced the notorious high/rough idle. I tried the "key/pedal dance", "just drive it", and "brake press and hold" methods several times with no kind of luck. The fear of having to buy a new throttle body or ecu was enough to keep me trying and after many many manyyy tries I ACTUALLY DID IT!

I found that it worked perfectly when I did the "Accelerator Pedal Released Position Learning" --> "Throttle Valve Closed Position Learning" --> "Idle Air Volume Learning" procedures exactly one after the other. Before starting I made sure the following requirements were met:

PREPARATION
Battery voltage: More than 12.9V (At idle)
Engine coolant temperature: 70 – 100°C (158 – 212°F)
Park/neutral position (PNP) switch: ON
Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
Steering wheel: Neutral (Straight-ahead position)
Vehicle speed: Stopped
Transmission: Warmed-up

I made sure these were met just by going for what felt like a pretty unsettling drive to get the car nice and warm. Since I have a manual I kept the clutch to the floor the entire time as I though it could be considered a neutral start switch. After that my successful procedure went like this:

OPERATION PROCEDURE
1. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
2. Make sure that accelerator pedal is fully released.
3. Turn ignition switch ON and wait at least 2 seconds.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON and wait at least 2 seconds.
6. Turn ignition switch OFF and wait at least 10 seconds.
7. Turn ignition switch ON.
8. Turn ignition switch OFF and wait at least 10 seconds.
9. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
10. Repeat the following (a and b) quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
11. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops blinking and turned ON.
12. Fully release the accelerator pedal within 3 seconds after the CEL turned ON.
13. Start engine and let it idle.

I was extremely relieved to see my idle drop all the way down to about 650 rpms. I hope that I helped some people and put some doubt and confusion to bed in the process.

If there's anything I missed or any questions just ask!

 

Nice work! Appreciate you taking the time to type this up. Someone may find this very useful one day.