So I have a 07 G35x, and during cold starts the car usually idle a bit under 2000 rpm when I first start it and dips down as the car warms up. After the coolant reaches operating temperature it's usually at 800 or 900 rpm. I was wondering if this is normal? I'm planning to clean out my throttle body today and see if that helps. Thanks for the input!

 

Honestly mine does the same thing. So Id assume it's completely normal

 

It's normal... cold starts always idle high at first.

 

Yes normal. Every car has a higher idle on cold starts. Its part of the start up sequence to solve typical cold engine problems, these settings are usually predefined most of the time in modern FI set-ups. If you have ever started an old 2 stroke outboard motor, you need to pull the choke to cold start for similar reasons.

 

thanks for the input guys so after cleaning my TBs I have a engine code now haha. going to pull the code and hopefully just need to do an relearn

 

u kept the TB plugged in, or touched the butterfly doors didn't u?

 

TB was fully connected and I did not press on the butterfly doors at all just gentle cleaned them with TB cleaner and some microfibre. Pulled the code P0507 Idle air control system RPM higher than expected. Nothing serious probably just have to drive it for awhile or just do a relearn.

 

This forum hates touching the TB. Unplug, clean (move TB), plug back in, drive

 

Ahh kk cool. Thanks for your help

 

Along the lines of warm up sequence..... I'm not sure if the G does it since I have a manual however most auto cars don't shift into higher gears when cold to help warm up faster.

 

I saw your P0507 error code thread, but it's now closed.

This thread covers the idle relearn procedure ad nauseum : https://g35driver.com/forums/v36-diy...le-bodies.html

And here's the FSM for the procedure straight from the factory: http://www.nicoclub.com/FSM/G35/Sedan/2007_G35_Sedan/ Note: see section "EC" (engine control) pages EC-17 through EC-19.

In all likelihood, if you've messed with your throttle body, you will need to have an idle relearn procedure successfully completed on your car. The trouble is that the ECU's in these cars can't learn for ****. It is just a crap shoot if you will be one of the lucky ones or not and have the car respond like it is supposed to. I know a lot of people probably just bungle the pedal procedure, but there are definitely problems beyond just simply mistiming the counting of the pedal steps; SOME CARS JUST WILL NOT WORK EVEN IF YOU DO IT PERFECTLY !! The dealers also have trouble with them, and that's even with the use of the Consult diag systems them have!

Try doing the pedal dance and see if you can get it. If not, go ahead and drive it a few days to see if it will get any better. As a last ditch, you can "lobotomize" it by leaving the battery disconnected overnight. If you still can't get it to fully come down to 650 rpm, then you need to think about having a dealer try it with the Consult system. If you do, I'd suggest a Nissan dealer (cheaper), unless you have a particularly good relationship with an Infinti dealer such that they will not gouge/rape you.

I've personally watched a "simple" idle relearn procedure occupy an entire shop of 4 journeyman techs, pulled off all their other cars in the shop at the time, huddled together over the course of 3 hours, just to try and "trick" the ECU in an '07 sedan into cooperating with the idle relearn procedure. In those kind of situations, some dealerships will just bail and tell you that you need a whole new ECU!!

The time I watched them, they used the Consult system and had to perform the operation over and over repeatedly while they first pulled one, and then another fuel injector pigtail; essentially crippling the engine's ability to idle any higher. It was only then, by means of abnormally suppressing the high idle, that they were able to get within an rpm range where the ECU could complete a relearn procedure. Apparently, even with those methods, it was not able to be completed in a single relearn, but had to be done repeatedly in incremental relearning steps. They could only get it to improve by 100 rpms or so at a time, so they had to just take it in stages and repeat the process over and over until they finally got idling back down to normal.

Good luck and let us know how it goes.