Hello forum, I have a 2004 g35 coupe with about 48,000 miles on it. I disconnected the battery and hooked it up to a charger and let it charge for 6 hours. After charging of the battery is completed, I reconnected the battery to the car and started up fine. What I notice is that after turning the car off and starting it back up again it has a hard time starting. The car would start then as soon and I turn the key to the on position the RPM would drop and then stall. I would have to give the car some gas to prevent the vehicle from stalling. My question is what could be the cause of this issue. And has anyone have this issue? Thank you in advanced.

 

Does it do this everytime or just when you start, stop, and try to restart it? I'd start with the basics: fuel, air, and spark. Since, you have to press the gas maybe an injector is dirty or the fuel pump is iffy. Do you have any CEL?

 

Before the battery was removed it didn't have this issue. Now its doing it about every time. There's is no check engine light displayed and replaced the plugs around 30k miles. Could this be do to the fact that i've removed the battery and the ECU has to relearn everything again?

 

Nah, I don't think that should have anything to do with the ECU learning everything again. I'd double check your positive and negative connections. Do you have a multimeter to check the battery voltage?

 

If it starts fine cold, but not when its already warm its a dirty throttle body. EGR gasses muck up the hinges on the butterfly and just need to be cleaned off.

 

this video show the exact problem, starts up and stalls.

as Gdirtyfive55 says the throttle body needs to be cleaned. Does anyone know the proper way of cleaning it? I've never done anything like with electronic throttle body before.

 

In his own thread he admits disconnecting the battery for six hours, the ECU forgot why it's there and what it's job is. By doing a reset, that should correct all your ills. Our battery's shouldn't be disconnected for more than an hour or two maximum...Gary

 

https://g35driver.com/forums/showthr...548&styleid=51

 

I guess you can try these steps before trying to clean the throttle body:

Accelerator Pedal Release Position Learning

Operation Procedure
1. Make sure that the accelerator pedal is fully released.
2. Turn ignition switch “ON” and wait at least 2 seconds.
3. Turn ignition switch “OFF” wait at least 10 seconds.
4. Turn ignition switch “ON” and wait at least 2 seconds.
5. Turn ignition switch “OFF” wait at least 10 seconds.

Throttle Valve Closed Position Learning

Operation Procedures
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch is “ON”.
3. Turn ignition switch is “OFF” wait at least 10 seconds.
Make sure that the throttle valve moves during above 10 seconds by confirming the operating sound.

 

*sigh*

Just clean the tb

 

I doubt his ecu forgot why its there. My G went without having power for days and worked fine when I put a new battery in.

 

I never understood this logic.
Both of my vehicle's batteries are disconnected before going into long term storage each year without any issues.
Please explain how an inanimate object can "forget".

 

Not sure why you say that. It's pretty common to disconnect a battery from cars or other vehicles in general for storage reasons for way longer time periods than just a few hours. I do it every year in my G and all of my motorcycles for 3-4 months. They all work fine in the spring when I reinstall them as long as I have them on a trickle charger in the winter and stored in a climate controlled environment. Mechanics regular do this too while doing big repair jobs on a car.

 

Before I got my Osiris tune I was throwing a lean condition warning and decided to disconnect my battery over night. Next morning start up took a while and idle was below 300 rpm cold, my coupe was a mess. Went to Nissan where a friend worked, being trained in everything Nissan makes including the GT-R I believed what he told me. "Removing the negative side of the battery for several hours will make your ECU forget why it's there!" That is what happened to me, the fix didn't include cleaning my TB!
Gary

 

Well you just said yourself that your car was not running right before you disconnected the battery.... Disconnecting the battery overnight didn't make your problem, it just transformed the symptoms of an existing problem.

I think your mechanic buddy was just being facetious when he said that. Leaving it disconnected in our cars for a long enough period of time will cause it to lose any learned tuning parameters, but the ECU is just a computer with firmware running on it like any other computer, router or network appliance. If it loses that learned data due to prolonged power failure causing a RAM wipe, it just reverts back to the firmware's locked default values and will attempt to relearn them again from there.