Whats up fellow G's

So a little background first in the 10 months I have owned this car:
- Purchased the vehicle back in Aprilish last year, 2011 G37S 7AT Sedan.
- Been driving ever since and added on another 9,000 miles (Bought at 53k, now at 62k).
- I have had 2 oil changes since.
- Had the 60k maint done at Infiniti (as well as to look at car since purchased recently) at 57k. During this time, they cleaned my TB's as well (will get into this later).
- Had my battery replaced at 60k.
- Last oil change was at 61k.

Now, on to the good stuff !

So ever since around 55,000 miles, my car started to have problems starting. Meaning, it struggled to turn on sometimes caused by low RPMs. What happens pretty much is you proceed to start the car just as you normally would, but when the engine ignites, the RPM jumps to ~500-600 and dies / struggles to turn instead of the normal ~1000-1400. If you gave it gas, it would stay on instead of dying. This never happened on cold start but mainly on warm to hot days (varied). Now, this would happen everyone now and then up until around 56,000. Then it started to happen 3-4 times a week -- sometimes more.

Now, I got the problem "supposedly" checked out by Infiniti as I requested a 60,000 maint job (car has never been to an Infiniti by previous owner, only independent shops). I told them the problem and they mentioned that cleaning the TB's is the way to solve the issue. This is what some of you guys also said, so I thought it would be for sure solved. Got the car back and they said it was squeaky clean.

Now a week into the 60k, I started to have the problem again. Back on the level of happening "every now and then". I would say maybe 1-5 times a month. Called them back and told them about it. They said I could pay for another diagnostic but I said no thank you. I decided to change the battery on my own hoping it would fix it. It fixed it for a week, then it started to occur again.

Came across a thread about someone stating it could be the deadly blown rear timing gasket so I decided to get my car diagnosed for $185 since I'm under powertrain warranty still. Members said it probably wasn't a blown gasket but for sure a powertrain issue still.

SO I gave my car to the dealership yesterday for the diagnostic and received no calls unless I called. I called today and they said that my oil pressure was fine (took pictures of the sheets) and that they cleaned my TBs once again. Other then that, they said the car is perfectly fine. Now, the issue occurred still AFTER the first TB cleaning, so I'm assuming it will happen again. Does anyone else know any reason why this would be happening? Infiniti said the car runs clean but I don't think so. I'm not too sure, don't know anyone else with a G that I could compare the drive. I also get rough shifting.

SIDENOTE: How big of a difference is the 2015 QX50 compared to the G37 on a technological level. The loaner I got was a QX50 and man, it felt like a new compared to mine. On top of worlds SMOOTHER. No type of rough down shifts. And man, when put into manual mode, the car SHIFTED WAYYYYYYYYYY smoother and faster than my G37. No type of boggling when up or down shifting. My G37 gets really bad boggles as I upshift and downshift unless I do it a specific RPM (3kish). If I am correct, it is still the same engine and transmission? Just a little side note I've noticed. It's literally a different drive to the point where I would think it is a different engine / transmission.
SORRY FOR THE LONG READ AND THANK YOU VERY MUCH !!!!!!

 

Post a video so we can see what is going on when it starts, then we can chime in with our thoughts.

 

sounds like dirty throttle bodies. gotta be a little careful cleaning those, but it really sounds like that's what it is

 

My car did this about a month ago, and would stay stuck trying to start up. I finally gave it gas and it fired up and blew out a giant puff of smoke. It was extremely cold and the car had not been driven for a few days. It smelled like gas, but I assume the puff of smoke was due to excess fuel since it was cranking over. I cleaned my throttle bodies about two years ago, so I am probably due again. My car sometimes would start and then stall out, but my TB cleaning took care of that.

 

I have been having this issue as well. Dealer told me that the throttle bodies shouldn't be cleaned and did the Idle Air Relearn procedure. We will see if that fixes anything at all. I am under warranty so their next step is to replace the throttle bodies. Might be worth a shot to try since they have already cleaned your TB.

 

Going to the dealer to pick it up now. I'll try and get a video. Now, I'm debating if I should wait to try and get a video of it reoccurring then show Infiniti, or install my Ark Grip and see if it changes anything. But not too sure.

 

DON'T put on the exhaust! This may give the dealer something to blame the issue on.

-ALSO-
when you are trying to resolve an issue, you shouldn't add any mods. It just may complicate things and make it more difficult to resolve the issue.

I am certain that you are VERY anxious to put on the exhaust (I would be!) but it is best to make sure the issue if fixed first.

 

For the exhaust, I will put it on but the place who is installing it will put my OEM back on before I go to the dealership. All for 100$ total. But Ill wait tho.

So it turns out, I got 15 PSI at idle and 75 PSI above 1500 RPM. They cleaned my TBs again. At this point, they said I just need a video so they can send it to the higher Infiniti technicians to try and get a solution. The dealership was nice as I was suppose to pay $185 for the diagnostic if they didn't find anything (which they couldn't), but they said its on them since I've been to them multiple times in the last 7,000 miles.

So... Guess I need to record my engine every time I turn the car on. Will post footage when I get it