Anyone ever experience their car not responding during acceleration? Just swapped a low mileage 2017 qx50 motor with 21k into my 13 g37. Put about 850 miles on it and for the most part it’s been smooth!

This morning I was trying to accelerate and the car wouldn’t respond and when it tried to, it would rev slowly. This happened prior to the motor swap also. Thinking I need to update my ecu. Car was fine after I shut it off and got back in.

Along with that, I smell a burning smell coming from somewhere on the car. Can’t pinpoint where. I’m thinking tire because the car was recently lowered and is pretty low with no alignment.

 

Happens to me as well sometimes, maybe once in a couple months. Transmission + ecu sometimes bug out and puts you in a higher gear, I hate when that happens. Your tire is probably rubbing.

 

infiniti is going to charge
$160 to update my ecu. I’m hoping that I need an update because if not, I’d be wasting $160 lol

 

Next time this happens, put the car in manual mode and down shift manually to a lower gear. Does the car still lag and not want to rev in a low enough gear? That will let you know if you're dealing with a Trans issue or something else with the motor/wiring. What does your TPS, AFR, O2's, MAF, and voltage show when you're flooring it with no response? This isn't normal despite how buggy the 7AT is. It may take it a second to find the gear you want in DS or D, but it shouldn't lock in a high gear like that.

 

This is the first it’s happened in a long while. Maybe three months. It’s weird because this is corrected as soon as the car is shut off and back on. Next time I will go to manual mode. Going to my mechanic tomorrow and going to Infiniti on Monday to see if I need a software update. I doubt it is a wiring issue because the old engine did this also, unless it’s a bad harness but I think it needs an update. Hopefully... I have nothing to measure those things but I’ll speak to the mechanic about this.

 

Mine was already updated when I bought it. If it happens a lot, then just fork over the $160. If it happens once in a blue moon, like for me, then just leave it. You're using the G37's ecu and not the QX50's, correct?

 

G37 ecu lol.

 

My g37 would do the same from what I gathered most people say that's limp mode and it happened to me on the freeway once no matter how much I floored the gas the car wouldn't respond until I was able to pull over shut it off and it ran perfectly fine after that

 

My car at times has a similar problem to what you're describing. It's particularly bad while the engine is still warming up and shortly after the gage gets to and stays at running temp. Even though the coolant has reached running temp doesn't mean the entire engine block is at the same running temp yet. My theory is that the different temps in the engine cause issues and the engine just doesn't like this. I'm unsure why this wouldn't cause a CEL as it basically throws the car into limp mode under 3-4rpm depending on the car's mood lol
Next time you drive, try not doing any hard accelerations even when the gage shows you've been at running temp for 10 minutes.
I'm thinking about swapping over to a cooler operating temp thermostat. For one I don't want to overheat in the summer cause I like to drive the car pretty spiritedly, plus it could possibly help with this issue.
After about 20-30 minutes of driving you should be free to do whatever you want. Winter seemed to have made this issue worse as well, which makes sense if my theory is correct because the cold air would keep the outside of the engine cooler than the inside (for obvious reasons) where during summer heat soak is much more prevalent and keeps everything pretty hot under the hood keeping temps more even in the block.