Barveyy

what’s up y’all, i’ve had my G37s (MT) for about two years now and i noticed recently when i step on the gas the initial response is slow and not as responsive as i remember it

on top of that my car has been running a little rich (not burning though) and you can especially smell it when i run it against someone which i don’t do anymore so i don’t damage anything,

i asked around and ppl are saying it might be my fuel injectors? which i looked up and sounds right but i want to know if any G owners went through this and can throw some knowledge at me and maybe cost for the repairs

thanks 🙌🏽

jfridge92

When is the last time you performed a tune up, specifically changing your plugs? If the plugs are old and fouled out, it's very possible you aren't getting a complete burn in the cylinders which can cause the car to run rich.

Also, when's the last time you cleaned your throttle bodies and performed an idle air relearn and throttle closed position relearn?

Are you throwing any codes even if it hasn't set a check engine light?

Barveyy

i’m going to have a look at the spark plugs make sure they are straight

maybe over 10 months since i cleaned the throttle body but i never did idle air relearn or closed, i have no clue what those are could you provide a link or video?

and i have not checked the system yet but i’m going to, this is all great advice man i appreciate you

Surfnazi

Clean your maf and run 2 cans of bg44k back to back. Change your plugs if you're close to 100k miles

jfridge92

Check out MotorvateDIY's youtube channel. He has a video showing two ways to re calibrate your throttle bodies with either an app for android or doing the pedal dance with the accelerator pedal to relearn them. That will make a difference if never done after cleaning the TB's.

I second checking and changing plugs if they haven't been done near 100k.

Also, you are using premium fuel, right? If you run 87 or even 89, you run the risk of spark knock which can cause the ECU to retard timing and make the car feel sluggish. You'd be surprised how many VQ owners ignore the nice pretty sticker on the fuel door that says premium unleaded only and just pump 87 in.


Also, when you have the plugs out examining them, look on the insulator (porcelain) of each plug and look for any burn marks. This could indicate a small crack causing a misfire. Also examine each of the coil boots very closely, again looking for any burnt or discoloration on the inside and outside of the boot. This could indicate a small tear that can cause spark to jump from the coil to the spark plug well instead of down the plug and cause an intermittent misfire.


Finally, do you have any way to scan the car in real time? I'd be interested to see what your throttle position is reporting when you floor it and get the lag. O2's could also be going and cause hesitation, all of which can be seen with a live data scanner like Torque, OBD Fusion, etc.