AGHHHHHhhhhh!!!! I've had this stupid car for 8 years, have been freaking meticulous with everything, not letting anyone but me work on the car. So I replaced my spark plugs, clean my MAF, filter then the TB and bam High Idle. **** me right for trying to maintain this stupid car. Ugh... dammit and I've done the stupid reset multiple times, it worked once, but when I turned the car off and went to drive the next day, the high idle returned. ****ing stupid car. dammit.

 

LOL, but seriously I did the exact same maintenance not too long ago.

Try these steps:
1) ECU Reset Procedure
2) Accelerator Pedal Release Position Learning
3) Throttle Valve Closed Position Learning
4) Go drive car around for 10 minutes to everything nice and warm, THEN
5) Idle Air Volume Learning - Don't forget to rev engine 3 times to between 2K & 3K rpms to "save" the target idle.


My 06 6MT is over 150K miles, throttle body was NASTY behind the butterfly. I disconnected battery, unplugged TB, then removed it to clean it. I moved the plate a whole bunch of times in order to get a tooth brush in there to remove all the gunk. I was idling around 1,800 RPMs at first. I did the Idle Air procedure after just letting the car warm up, couldn't get it to idle below 1K rpms. Only after taking it for a drive and then trying again was I able to get it to drop to the proper 650. No more rough idle at stop lights, and no more stuttering while using cruise control going downhill on the interstate.

Full procedures are listed here: http://www.technosquareinc.com/350reset.htm

 

Did you move the butterfly plate? Some people claim that can ruin the tb

 

I've moved the butterfly all the time, nothing bad happens

 

^Same here

 

I didn't say it will. Just some have had it happen. But it was probably cuz it was sticking open cuz it wasn't cleaned completely or the spring was worn. There's always a possibility

 

I moved mine and it was fine but mine only had 60k on it when cleaned. Higher mileage increases the chances of a failing tb, I'm sure

 

Actually contrary to popular belief the Throttle Bodies on the G35 are very strong and durable....I had the same problem on my 2007 infiniti G35s where the Throttle Bodies were cleaned and after the residue was removed it would idle high and would not go below 1,500 RPM, and would sometimes stay at 2,000.

Opening the valve does absolutely no harm, and there is no need to be gentle, I am a technician and have taken them apart, and in doing so one can find that they are driven my a very powerful motor and the gears that turn the valve are made of thick metal and look like they could drive a transfer case.

However to answer the problem of high Idling after cleaning the TB's here is what I do......

On the "Intake" side of the TB on the top there is an adjustment screw, this will adjust the idle position of the intake valve. After it is clean the computer sets the valve to be too far open when idling, and will stay this way even when the junk is gone, allowing too much air to pass through. Adjust the screw so that you can just move the valve a tiny bit when you push it with your hand, so that it is nearly "Sealed"
Do exactly the same to the other side and put it all back together.

After this turn the ignition on once, turn if off, and then start it and your done. It will now idle much lower if you did it correctly, and if it is still a bit too high re-preform the procedure and close it a little more.

Hope this helped people who had the same problem I did a while ago, just wanted to let you all know that there is no point in wasting money on new TB's, as there i nothing wrong with the ones that were taken out, they are merely out of adjustment.

Good Luck,

 

Actually contrary to popular belief the Throttle Bodies on the G35 are very strong and durable....I had the same problem on my 2007 infiniti G35s where the Throttle Bodies were cleaned and after the residue was removed it would idle high and would not go below 1,500 RPM, and would sometimes stay at 2,000.

Opening the valve does absolutely no harm, and there is no need to be gentle, I am a technician and have taken them apart, and in doing so one can find that they are driven my a very powerful motor and the gears that turn the valve are made of thick metal and look like they could drive a transfer case.

However to answer the problem of high Idling after cleaning the TB's here is what I do......

On the "Intake" side of the TB on the top there is an adjustment screw, this will adjust the idle position of the intake valve. After it is clean the computer sets the valve to be too far open when idling, and will stay this way even when the junk is gone, allowing too much air to pass through. Adjust the screw so that you can just move the valve a tiny bit when you push it with your hand, so that it is nearly "Sealed"
Do exactly the same to the other side and put it all back together.

After this turn the ignition on once, turn if off, and then start it and your done. It will now idle much lower if you did it correctly, and if it is still a bit too high re-preform the procedure and close it a little more.

Hope this helped people who had the same problem I did a while ago, just wanted to let you all know that there is no point in wasting money on new TB's, as there i nothing wrong with the ones that were taken out, they are merely out of adjustment.

Good Luck,

 

I just bought an 08 G35x and I noticed something wasn't right. On cold starts it would start up fine, hold at about 1200 rpm and then drop down to about 700 and then jump from about 650 to 750. On a warm start it would hesitate pretty bad and eventually turn over and then settle in the same way. My car prior to this was a Maxima so I had an idea of what was going on because I had to clean the TB in that. After some research I was sure and went and got everything. 2 new AF's, TB cleaner and MAF cleaner. Took it all apart, cleaned it, put it back together, no issues. I started to drive it and the idle was better already and acceleration was improved. I did start to notice that when I let off the throttle that it would almost feel like I was applying the brakes or I was downshifting. My thought was maybe now that it's clean the butterfly valve is sealing properly and there's less are getting through than there was when the valve is closed compared to when it was dirty. I did all 3 relearn procedures and luckily all 3 were good on the first try. (Only 2 of which I can be sure of). Drove it and it seemed better for a few days and all seemed well. Now when I start my idle goes up to almost 2000 and slowly settles to around 700. Also, it's back to jumping from 650 to 750 at idle with the a/c off. 750 to 850 with a/c on. Never had a CEL. Checked for vacuum leaks and couldn't find anything. Any ideas?

 

Mileage? High mileage could point toward a bad tb

 

It's got 97,XXX. Funny that you mention that because now that I think about it there was something clicking in the passenger side TB when I pulled it to clean it. I didn't think much of it at the time. If it need to be replaced it's no big deal but I just want to exhaust all my other options first.