I've got kind of any odd situation going on with my VQ35 and I figured I'd throw it out there and see what you thought. Basically, a couple weeks ago I decided to switch out my stock plugs for a set of NGK Iridiums in the standard heat range (5) since my perf mods aren't too extensive at this point. I got a good price on them and I figured what the hell, might as well give them a try and see if I notice any improvements. Overall, the car performs well at normal operating speeds and WOT, but at idle its a totally different story. It starts out idling pretty low, at about 400 rpm. Then, it drops further, as far down as 200 or a little below. The engine shutters a bit, and the RPMs will climb close to 400 and go back again. Weird thing about is the fact that the engine isn't shutting off or throwing any codes. I did do an ECU reset after installing the plugs, so I figured the ECU hadn't properly adjusted but I've tried high sustained revs in neutral and have put a lot of highway and city miles on since the install, about 250. Really weird, don't understand this at all. What do you guys think?

 

id switch the plugs back out to stockers OR i would see if the dealer can tune your idle RPM up. I know another member who had issues pertaining to idle RPM's and teh car stuttering but it wasnt related to his plugs. He/she had like installed a S/C or some major mods that caused his idle to fluctuate and idle lower than normal.

 

are you sure that it's dipping down to 200 rpms? the first minor mark on our tachometers indicate 500 rpms.

 

Yeah I'm positive about it, but nevertheless I appreciate the help. I think I'm going to eithier do what you said P and put the stock plugs back in or take it to Lokey Infiniti here in FL since they're the only ones that support mods here in the state. Thanks!

 

take it to any nissan or infiniti dealer,they will raise your idle for a fee.i think it under $100