When I come to a complete stop an go to accelerate the car "stutters" or "hesitates" before it actually begins to go once it's going drives perfectly fine I had the transmission looked at today an there's nothing wrong with it. Iv recently changed spark plugs in coil packs where still in good condition no excessive wear or smell no oil in any of the chambers. There's no check engine light I'm beyond baffled on it anyone have a idea?


EDIT!!!!!! Cleaned throttle bodys new filters all around new fuel pump,front propeller saft U-joint,engine mounts, transmission mounts,all fluids topped an replaced valve cover gaskets replaced.

Described more... Iv noticed that when I let off the gas completely even going down the road the hesitation when pressing the gas is there again. For example in traffic it's doing it constantly. It only does it if I give it little gas. If I step on it there's no hesitation even from a dead stop. I haven't had any sensors replaced. My check engine light did come on for a day an it threw a P0420 but then it went away an hasn't came back going on 2 days. I haven't had my cats looked at yet bc I was fixing everything listed above in the edit hoping it wasn't them an I'm trying to rebuild this car anyways. Cats are so expensive.

 

Disconnect the battery for a few minutes. This will reset the computer and initiate a relearn for the way you drive. In addition clean the throttle bodies while the battery is disconnected. DO NOT move the throttle butterfly disk manually. Just spray the throttle body cleaner around the edge of the butterfly disk. If you do open them, you may have to do the throttle position relearn procedure. Do a search on this forum, I believe there are instructions on how to do this in one of the threads.

 

"Steven" I did so the throttle body was definitely dirty I didn't mess with the butterfly disc but I'm still having the same issues still has "Hesitation" from a stop an when I go to accelerate I'm wondering if it has to do with fuel injectors or something along those lines

 

You can try using a fuel system cleaner like Techron by Chevron. It will clean the fuel injectors. You can try the throttle relearn procedure, it is described in detail in one of the threads here. If you can do a search it should pop up. You may also access the service manuals in the link below.
https://www.nicoclub.com/infiniti-service-manuals

 

I had it scanned today an the engines burning lean maybe the fuel pump/filter? Iv noticed that the filter is built into the pump in this vehicle so can replace just that hopefully getting the pump replaced it fixes the issue. I also had my ignition switch fuse blow while scanning it earlier not sure on why it blew

 

Before you go to the expense of the fuel pump replacement, have the fuel pressure checked on the fuel rail. It could just be the fuel pressure regulator. Go to the fuel system section of the service manual on the link I posted earlier. If there is an issue with the fuel pressure or fuel supply, you will get bucking at highspeed acceleration when fuel demand is higher than starting off from idle

 

I went ahead and replaced my fuel pump since it's decently high in miles, I also went an got a fuel pressure test done an a bumper to bumper inspection by Infiniti. The fuel pressure test came back great. I do have a broken engine mount an a loose front propeller saft U-joint. Other than normal things like tires brakes ect came back good. Best $250 I spent taking it to the stealership haha

 

Well update an $1,300 later still having the same hesitation from the start am no check engine light. I replace both engine mounts, transmission mount,propeller usaft joint, an ch axle. I'm so confused on what it could be I'm done sunk almost 3k into trying to fix it an replaced everything the diagnostic test flagged an still same issue...... This is a love hate relationship with this car.....

 

Check for possible air leaks. Rubber hoses have the tendency to dry rot and split, so check them very thoroughly. Looks like you replaced many parts. If you disconnected the battery to reset the computer and did the throttle relearn procedure and the throttle body is clean and still have the issue, you may consider replacing the throttle body, or at least remove it and give it a real good cleaning. Make sure you disconnect the battery before unplugging any of the connectors. Does it hesitate when you rev the engine with the transmission in neutral? If it doesn't check the transmission fluid level. I know you said that you had the transmission checked on your initial post, but check it again.
A few years ago, I purchased a 2007 G35x for my wife that had just under 20K miles on it. It had the same issue, so I disconnected the battery overnight and started driving the following day. After a day or two the hesitation was gone. We sold the car two years ago with 140K miles on it and never had the hesitation issue.

 

I spent a good amount of time with a mechanic friend of mine Saturday an a little Sunday trying to find any sort of vacuum leak we tried multiple different methods an none came to the conclusion it had a vacuum leak. An to the question if it does it in neutral No. It only does it in drive an when the cars at a complete stop an try to accelerate. If I give it decent amount of gas it doesn't do the "hesitation" I'll try disconnecting the battery tonight an reconnect it in the morning. Not sure what else I can do other than take it into a expensive shop an have it looked at Iv spent lots of hours an decent amount of money trying to do it myself.

 

Have you fixed this issue? I had similar hesitation under part throttle due to my ECM software being out of date by a decade. I've updated it myself to the newest firmware using Nissan NERS and IDS Ford VCX. It cost me $45 for firmware and now the car runs a lot smoother and no more hesitations..

 

No I haven't fixed this issue still deal with it everyday. Iv taken it to infiniti an there dumbass's say theres nothing wrong with it ill try an get the ecm updated

 

Here, read this thread about ECM update at home, I start in post #4.
Guide for Reprogramming Updates to your ECU