Hey guys I noticed my 03 G35 would cut out and feel like its missing a little bit when cruising part throttle down the road. Also when driving and coasting if you throw it into the neutral the car will just cut off. I knew it was almost time for a tune up so I went ahead and changed out the plugs, clean the tb, mass air, and air filter but even after that the car has the same stumbling and cutting off issue. It hasn't thrown a check engine light and I even took it to a Infiniti specialty shop but even they couldn't figure it out. I know how these cars throttle bodies gunk up easy and figured that was the problem but obviously not. I'm thinking maybe its a coil pack going bad, mass air meter, or maybe the throttle body itself is messed up. I don't want to start guessing and throwing away money at it. I love this car and have had it for over 6 years. Car has 152k and has been mostly trouble free its whole life. Anybody has any ideas or experience with a issue like this?

 

Does the car stall everything you put in neutral while cruising?

 

If your on the throttle driving and then throw it in neutral to coast it stalls and shuts off. When driving at part throttle you can feel it missing and stumbling a bit. If you floor it the car feels fine from what I can tell.

 

Might be a camshaft position sensor (you have 2) or the crankcase position sensor going bad. These will start to fail and not throw a code or the SES light for a while. They are pretty easy DIYs so something to check. I'm at 120K and really expect to have to deal with these sooner than later.

 

Wouldn't a bad camshaft or crankcase sensor throw a code though?

 

sorry, just noticed you said they usually won't throw a code for a while. I might just wait till it throws a code so that i'm not throwing money away guessing. Thanks for the help though.

 

No worries, that's why we're here. Let us know if you figure it out.