Originally Posted by heyn

Hello guys. I have Infiniti FX37S 2009 since 2009, bought it brand new. I guess I'm having throttle problems since they have never ever been cleaned since I bought the car LOL.

The problems I have are - when I'm on traffic light and waiting the RPM are moving from 500 to 1100 constantly. When I'm pushing the break the RPM's are going up and I have to push it harder to stop the car, and when release the break the RPM's are going to 1200-1500 and car is speeding without hitting the gas pedal. Another problem is fuel consumption got insane, it's 27-30 litre per 100 KM (used converter and it's 8 mpg for US people) city driving.

Was in the Infiniti service and they did a diagnostic on the car and told me everything is perfect, no errors, no problems. I will go again to the dealer and ask if they can clean the throttles since I'm not sure I'll be able to do the relearning thing - my english ins't my naive language and I can't understand the relearn explanations well.

EDIT: the car is at 250000km

Originally Posted by Tatus

Spray the maf sensors first it's probably them giving you surges

Originally Posted by heyn

Hey Tatus! Alright, I'll buy MAF sensor cleaner and just spray them without using tissue or anything? And should I unplug them, or I can spray them while plugged?

Thanks!

Originally Posted by Tatus

Unplug and remove them. Spray the plate that's inside but don't touch it. Let it dry and reassemble. I use crc maf cleaner

Originally Posted by Q8y_drifter

Nissan throttle bodies are notorious for getting dirty pretty quickly. If your car has issues with the RPM dropping at idle, it is probably a dirty TB.

Items Required:
- 8mm socket wrench
- 10mm socket wrench
- 5mm allen key
- Clean towel/rag
- Throttle body cleaner
- Pliers (optional)
- 2x throttle body o-ring seal (optional)

You will need to have the engine cool down before you start working. First you'll need to remove the engine cover. If you have a FSB like me, you'll need to remove that first. Simply take off the aluminum bar with the required allen key.

Attachment 171384


Next you'll need to remove both intakes to access the throttle bodies. It is best to clean one TB at a time. Removing the intakes will depend on what type you have installed.

Attachment 171385


Once you have removed your intake, you can see the TB and the butterfly valve inside (golden). You shouldn't see much dirt yet, as most of it loads up behind the valve. To take off the TB, you'll need to remove four hex bolts as shown below with a 5mm allen key. use the star configuration when removing and installing these bolts. They will be tight since they have thread lock applied to them.

Attachment 171386


Once you have removed these bolts, take care when pulling off the TB since there is an o-ring seal on the plenum. The TB will also have a connector for the throttle position sensor as well as two tubes connected to it. DO NOT disconnect the harness connector or any of the tubes. You should have enough space to work with. If you do, the ECU will not recognise idle throttle position and will cause the car to idle and run poorly.

Attachment 171387


You can see all the dirt on the other side of the TB. It is really sticky tar and will need some nice scrubbing with a towel and a TB cleaner to remove it.

Attachment 171388


There will also be some carbon/tar deposits on the plenum side as shown below. It is the greyish stuff on the lower portion.

Attachment 171389


To clean the TB, spray some of that TB cleaner (you can also use a very mild degreaser) on a clean towel. Push the butterfly valve to access all the necessary areas and start scrubbing it off. Once that is done, it should look good as new. Below is what mine looked like after cleaning. I also did the same for the plenum. Do not spray the cleaner into the plenum!

Attachment 171390


If your car has seen a lot of miles, it is a good time to replace the o-ring seal between the TB and the plenum.

Once the TB is clean you can now reinstall everything in reverse order. Repeat the same process for the second TB.

Edit: Made a video of the process below

https://www.youtube.com/watch?v=BIjOhJSJN_8

Hope that helps