Cleaning electronic throttle body

[mclasser]

I want to clean the throttle body in my 02 I35 with 84K miles because Nissan TBies are known for getting dirty quickly. Some people say you should never use your fingers to push open the throttle plate when cleaning electronic TBies, while others say this is not a problem. My car has various re-learn steps to go through after the TB is cleaned but some people say they dont work and require the dealer to reset things with their scan tool. Needless to say, I'm conflicted about what to do. What're others' experiences with this?

 

[actionstan]

If you removed the negitive battery cable wouldn't that prevent it from being messed up?

 

[Olas]

have someone sit in the car and use their foot to modulate the throttle..did this on an old beater polo today, took the air filter off and gave it quick short bursts with brake cleaner - just enough to make it start to bog then let it clear out and give it another squirt. it'll be squeaky clean in seconds.
redirecting the pcv and blanking your egr will keep it cleaner longer

 

[Tegger]

Originally Posted By: mclasser
Some people say you should never use your fingers to push open the throttle plate when cleaning electronic TBies

Is this a drive-by-wire throttle body, or one with an ordinary steel cable between gas pedal and throttle plate?

 

[bdcardinal]

When I cleaned the fly-by-wire throttle body on my 04 Volvo R car, I took it off the vehicle and cleaned it. The amount of stuff that came flying off was crazy. The car drove a lot better with it clean.

 

[Keith_Stone]

Originally Posted By: mclasser
I want to clean the throttle body in my 02 I35 with 84K miles because Nissan TBies are known for getting dirty quickly. Some people say you should never use your fingers to push open the throttle plate when cleaning electronic TBies, while others say this is not a problem. My car has various re-learn steps to go through after the TB is cleaned but some people say they dont work and require the dealer to reset things with their scan tool. Needless to say, I'm conflicted about what to do. What're others' experiences with this?


Not a issue with my 05 Chevy truck. It's a electric TB, alum body with a brass butterfly.
I remove the 4 bolts and lay it over on a shop rag and clean from both sides while not removing wiring etc. I move the throttle plate manually while cleaning. I've done this about 2-3 times since new.

 

[yonyon]

Originally Posted By: actionstan
If you removed the negitive battery cable wouldn't that prevent it from being messed up?


No. The problem is that over a period of several years the ECU learns to use a slightly wider throttle position to idle. The Nissan ECU is not programmed to accept a suddenly clean throttle body (regardless of whether or not the battery is connected) and decides that there's something wrong with the engine making it idle too fast. Assuming that you broke the engine, the ECU stops adapting/learning. One can explicitly tell the ECU to relearn the idle but it gets tricky because if the ECU sees too high an idle and decides the engine is still broken it will abort the relearn. There are ways to deal with this but in keeping with longstanding Nissan tradition, idle speed can be a pain. A hot towel can help.

The easy way out is to just clean it up a little bit, let it relearn then clean more until it's as sparkly as desired.

Also: One nifty feature of a Nissan with drive by wire is that when it has no idea how to idle it can also surge whie driving along at what should be a steady-state cruise.

 

[mclasser]

Originally Posted By: yonyon
Originally Posted By: actionstan
If you removed the negitive battery cable wouldn't that prevent it from being messed up?


No. The problem is that over a period of several years the ECU learns to use a slightly wider throttle position to idle. The Nissan ECU is not programmed to accept a suddenly clean throttle body (regardless of whether or not the battery is connected) and decides that there's something wrong with the engine making it idle too fast. Assuming that you broke the engine, the ECU stops adapting/learning. One can explicitly tell the ECU to relearn the idle but it gets tricky because if the ECU sees too high an idle and decides the engine is still broken it will abort the relearn. There are ways to deal with this but in keeping with longstanding Nissan tradition, idle speed can be a pain. A hot towel can help.

The easy way out is to just clean it up a little bit, let it relearn then clean more until it's as sparkly as desired.

Also: One nifty feature of a Nissan with drive by wire is that when it has no idea how to idle it can also surge whie driving along at what should be a steady-state cruise.


This is exactly why I am nervous about cleaning it. Nissan DBW TB's really don't like holding the proper idle afterwards. Some people on Maxima.org say disconnecting the battery after the cleaning may or may not help store the right idle speed. I really don't want to end up replacing my TB or paying the dealer $100 to reset everything if things go south

. So is there really a safe way to clean these freakin things?

 

[yonyon]

If it's very dirty and you don't want to deal with the relearn thing, just clean a little bit and then wait a few days. Repeat as necessary.

 

[Cujet]

I'd push it open and clean it with spray and a very, very soft bristle brush.

Yes, some vehicles have a special coating on the throttle plate. Guess what? That coating is rendered 100% useless when the throttle body becomes filthy after the first few months of use.

The ECU should manage the idle spead under any and all conditions. Think of it this way, what if you drive up pikes peak to 14,000 feet elevation? Does it need to re-learn? Or what if you live in Eagle Colorado at 7000 feet and drive to sea level. The air density is markedly different and the throttle plate position will be quite different.

 

[The Critic]

Originally Posted By: mclasser
I want to clean the throttle body in my 02 I35 with 84K miles because Nissan TBies are known for getting dirty quickly. Some people say you should never use your fingers to push open the throttle plate when cleaning electronic TBies, while others say this is not a problem. My car has various re-learn steps to go through after the TB is cleaned but some people say they dont work and require the dealer to reset things with their scan tool. Needless to say, I'm conflicted about what to do. What're others' experiences with this?

If it's a VQ35 throttle body, don't touch it. If it's working, just leave it alone.

We've had numerous issues with cleaning VQ35 throttle bodies on the G35. Not sure if the I35 will have this issue, but considered yourself warned. There's seriously a 50/50 chance of developing problems. The idle air volume relearn doesn't always work. We've resorted to replacing throttle bodies and sometimes subletting the car to the dealer to reflash the ECM.

 

[Cujet]

Originally Posted By: Cujet

The ECU should manage the idle spead under any and all conditions.


I clearly know how to spell the word speed. Not sure exactly where my brain was during that post.

Anyway, it is interesting to hear about the cleaning problems with some throttle bodies. I am a bit of a risk taker, so I would certainly clean it if it were mine. The method of doing a small section at a time is also interesting.