I'm not sure if I'm searching the right words or not but I wasnt able to find what I was looking for. Anyway, I recently replaced all the spark plugs with NGK Iridiums and made sure the gap was .043. After installing them, the car drives perfect except when it's idling. It seems to hiccup a little at idle. Not exactly sure what the issue could be. I tried getting my car checked at Infiniti but I think they were trying to make a few extra bucks. All they said is they noticed the spark plugs are after market and that they recommend a fuel system flush or cleaning or something. I know the fuel isn't the issue so I'm trying to figure out what the actual problem is.

 

After installing new NGK's in my car i noticed this too. The idle is smoother but occasionally i get a little hiccup where the rpm jumps up just maybe 100 rpms from approximately 650-750rpm. No idea what it is but you'd think it shouldnt be a problem since now you have brand new plugs in!

 

Get this, I had such a problem a couple months ago where my idle rpm would gradually dip lower and lower until the car vibrated and then the rpms would jump up a couple hundred and restart the process until one day the car just stalled out. Turns out the problem was an improperly installed air filter, might wanna check that just to be sure because your symptoms sound the same as mine.

 

I'll take a look at that tomorrow, i just thought it was weird that it started happening after i installed the plugs, maybe taking on and off the air intake caused a air filter to move around, ill check it tomorrow morning and see how it goes

 

time to get it seafoamed!

 

Clean TB and mass airflow sensor. At least that's what several threads recommend a page or two back.

 

Filter is alright, ill clean out the throttle body this weekend n see how it goes

 

Check out this thread: https://g35driver.com/forums/v36-diy...le-bodies.html