I took the throttle bodies off and opened the valves all the way on both to make sure I could clean as much as possible. Didn't really feel like taking them off and only cleaning them a little bit so I poured seafoam on a rag to get the most I could then switched to cotton swabs to finish.

I would say it was definitely worth the slight effort. I spent some time reading that DIY thread as well before I went for it, just make sure to have the right tools before you start and it should go smoothly.

also agree on the octane, the engine calls for premium for a good reason.

 

I've cleaned mine twice now. Don't spray anything on the TB itself, spray onto the rag and wipe. You can move the butterfly plates around. Take the throttle body off, but leave it connected to it's wiring. I also cleaned inside the plenum where I could reach.

Haven't had any problems since. The idle adjusts itself after that, might seem a little high at first but it will stabilize to normal levels in a couple days.

 

Not for me? So you're saying the CNC TB's I sell and personally have installed on several vehicles around town plus the buyers I've sold to are just the luckiest people in the world! Damn I should play the lottery!! You're buddy had other problems, period.

O look, another perfectly running set on my buddy's g37 where I opened the bigger brand new butterfly plate.

 

Every ported set I've sold and installed including mine stabilized in seconds. I have a 13 370z and it took milliseconds. Two 08 g37's took like 1-2. These cars are extremely smart and fast learning with their on the fly adjusting or whatever nissan calls it. I'm sure mine was just faster because the processor or changes nissan made over time was just better in 5 years. I have zero worry of touching the butterfly because unlike most posts I see everyone just spits info back out they read somewhere. I don't do that! I have 100% hands on knowledge.

 

As with any electromechanical device there is a certain limit of tolerance. Obviously some have had bad experiences moving the plates while others haven't. I just cleaned mine and chose not to move the butterflies to prevent a "what if" scenario. Thankfully no issues.

I do know that if it were as cut and dry as some have implied, there wouldn't be a need for Nissan to publish:

"Idle Air Volume Learning" procedure;
"Accelerator Pedal Released Position Learning" procedure;
"Throttle Valve Closed Position Learning" procedure;
and many others for this car.

It is NEVER a piece of cake for everyone every time.

 

I finally got the courage to try and suffer any consequences. Everything I did was by the book and it worked well and was easy. I gently moved the Butterfly, just a bit to wipe the gunk around it on both sides. Any area that was dirty and black , I cleaned. Sprayed CRC on a Microfiber cloth. as suggested. Cleaned the valve surface too.
If I can do it and not screw up , anyone can...The car runs great now. The throttle response is actually crisp and the pickup is faster.
It was worth the 1 hour it took for sure.
One thing more... Use a 5mm STAR wrench as opposed to a standard Allen Wrench. The Allen did not work and you do not want to strip those heads.
Remove nothing but the rubber hoses and just move them aside...do not disconnect anything that has wires etc. There's plenty of room to work. Just be gentle and don't force anything.
My car is a 2008 G37S coupe, 60K on it.... so I cannot say how other cars will react.

 

^Good to hear that all went well. As you said "if I can do it, anyone can do it."

 

have cleaned TB's on many cars and always moved the butterfly valves, in order to get in and around and clean as much as possible, on both sides of the valve. Never a problem. And yes, the computer resets the idle plenty quick.

 

thank you!

and those relearn procedures are not because someone touched the butterly. they are there for other reasons.

 

I just did this over the summer and then swap my manifold both times I push the butterfly open and cleaned it and behind it, I have had no ill effects. To take them off just be careful the bolts are fricken plastic and strip easy( Hex bolt) and can be a PIA to get off if this happens I had to cut one of mine off after this happened because someone before me( pre-owned car) tried to remove the TB's and stripped two bolts.

BTW your not crazy about getting better MPG with 93, it burns cleaner= less throttle and more MPG.

 

93 doesn't burn cleaner really, gas is gas. 93 has higher octane which prevents predetonation. If you use a lower grade gas and detonate, the motor runs like crap and pulls timing. This crap running engine burns more fuel to run safely. 93 will make the motor run like glass = better MPG.

89 actually burns a little cleaner because gas is heptane and octane. That's 7 and 8 hydrocarbons. 89 has more heptane (7). The lower the hydrocarbon the cleaner it burns. Look at propane and butane we use a lot of. Burns clean right? That's because they are 3 and 4 hydrocarbons. Now burn gas, then diesel, then oil, then tar. The thicker and more hydrocarbons you burn the blacker and dirtier it is.

 

i recently cleaned mine as well because throttle was revving crazy.. first time doing it but i was able to do it. i think the issue with my car had more to do with dirty MAF sensor and not the throttle bodies but i figured id do them too. havent had the rev problem since! id say buy the MAF sensor cleaner and clean that if you are having idle issues.

 

im hoping everyone knows by now, YES, you can move the butterfly valve and NO it wont cause any problems. if you are cleaning its something you absolutely want to do to clean it properly/completely.

 

Something is causing problems after the cleaning for 50% of the people that do this...it may be the improper pattern tightening or torque of the throttle body, the disconnection of the battery, the maf or yes the butterfly valve. No one knows why some have no problem moving the butterfly valves and others do or if this is not the problem something else is...user error? No one knows for sure...until someone can pinpoint what is causing the need for the relearn for some and others nothing then it is an unknown variable.

 

So basically the Throttle plate shaft (what the butterfly valve is screwed to) runs through the throttle body and the end of the shaft fits into a keyhole in the TPS switch which is nothing more than a potentiometer.

The potentiometer regulates the voltage that's sent to the ECU. It is possible, on most cars, to adjust the TPS via two small set screws which are in a slot on the sensor (update, just looked, there's no adjustment on ours). Perhaps this is getting bumped or knocked out of synch vs. the other throttle body and causing issues. If one pushes the throttle plate past one of the set points while cleaning, it could cause issues.

Simply opening the throttle body is not going to change a thing unless excessive force is used or you're knocking something else out of spec. We open/close the TB butterfly every day while driving via the throttle. It's designed to open and close.

Another theory could be while cleaning, folks are getting some of the cleaner on the mass airflow sensor. Or leaks in the gasket, improper torque specs for the bolts, etc...

Also, I'd recommend taking the throttle bodies off when cleaning and use NEW gaskets for the TB to manifold connection. Too easy to leave a wad of gunk or something else which'll get ingested by the engine.

The learning procedure is so the ECU can determine what voltage represents closed throttle and what voltage represents wide open throttle. It'll have a lookup table with a fudge factor and if it's out of that range, problems ensue.