Hey guys,
Ive been having this problem on and off for a year now, with certain fixes working temporarily. When i step on the accelerator pedal (from 2k-3k rpm) theres always a slight hesitation, like the car is struggling to get moving. Then once it hits around 3k it accelerates like normal. Ive cleaned the throttle bodies, so i know its not that. Is it possible that the spark plugs need to be replaced/cleaned? The car is at 80k miles and has been running rich since about 50k miles when i got the intake (theres always soot on the rear bumper). Or is it just the summer heat/humidity here in South Florida that limits the amount of air? Thanks!

 

I don't know about all that stuff you mentioned but I can tell you there is a big difference when it's hot and humid outside. My car is a whole lot quicker and more responsive in the winter time.

 

It's the heat, my car performs much better as well when it's not as hot, I'm in AZ and 100 degree plus weather slows my car down drastically. I can't wait until winter and also my Stillen Gen 3 CAI will like the colder air

 

Thanks for the info guys, I knew heat made a big difference but wasn't sure the extent. Would heat soak be drastically worse on my Injen short ram? I think at this point the stock intake would perform better. When i feel the injen piping after i park its hot to the touch, enough so that you can't keep a finger on it without being in pain.

 

Best solution is an ecutek tune from Seb at SpecialtyZ

 

Heat soak is not the issue. You need to change plugs and fluids

 

The hesitation is much more apparent in my 08 coupe with 122k on it, when I'm consistently stopping and starting. Aka, running multiple errands, with my car turning on and off non stop for a few hours. Also, its much more noticeable in the blazing hot, Vegas summers too....especially while being stuck in traffic (eh our traffic in Vegas is nothing compared to). Come winter/fall, its not so noticeable. However, I changed my plugs at 50k and will be changing them again next month. TB's are clean, fluids are always consistently changed as well.Other then the hesitation, my car runs pretty solid.

 

My G37S runs the best at 70* with low humidity



Recent round trip from NJ to Florida a few weeks ago
The poor MPG while in Florida is clearly shown.
Four fill-ups on the trip down, poor MPG while in Florida, and four fill-ups on the return trip



Telcoman

 

Also clean both maf sensors

 

Same here, when the car is driving for the first time in the day it isn't noticeable at all. However i put techron fuel system cleaner in and that seemed to help significantly. Must be a combination of the heat and needing to be cleaned. Was there a noticeable improvement by changing the spark plugs?

 

Same scenario as me actually. Its fine in the morning and/or a cold start, but once I really start to run errands/turn the car on and off on a consistent basis, it becomes pretty apparent. The Techron Concentrate did help a bit though (Infiniti recommended it to me). Cleaning the MAF sensors didnt help me at all. Cleaning the TB just ensured a smoother idle. The sparks I will have to report back once theyre done - should be next weekend!

 

have you tried unplugging the battery over night? and then Drive it like a crazy person for a day or 2? sounds like the Driver throttle Controller Memory needs to be Reset. At Least that what is was for me. i have a sedan tho adapts to the person(S) driving style

 

I've tried that many times and its failed each and every, time.

 

if you have been running rich all this time and are aware of the condition you should also know that an excess rich mixture would mean the catalytic converter will get damaged. its more then likely the catalyst is partially melted and you are not getting full flow of exhaust gases. i would check your engine vacuum and see if you have exhaust backpressure.

 

yup dealing with the same problem