This alone tells me you have a throttle position sensor problem. Before poo-pooing the idea (you did after all ask for input) you might try the procedure.

 

I didn't poo-poo the idea. In fact, I suggested it myself. I hope it's that simple. Does anyone have a link to the procedure? Thanks...

 

Ah! Sorry. I misunderstood your "It's not gas, ECU adjustments, or VDC" comment.

 

from the FAQ/DIY section:

https://g35driver.com/forums/faq-diy/6538-ecu-resets.html


be sure and do any necessary warm up procedures beforehand...
..let us know how it goes.

 

Thanks. I'll try one or more of those procedures after the dealer has had a look. I'd do it now, but I don't want any stored codes to be cleared.

 

You may think I am crazy, but I really believe that you babied it too much those first 1000 miles!!!

I have broken in MANY new cars and motorcycles.
I learned right away that you have to go wot from day ONE!

The engines that I have driven hard from day one run strong as an s.o.b.
and burn no oil!!!

My 03 maxima auto ran a 14.780 BONE STOCK, burned no oil and EVERY time I drove it, it felt like it was telling me that it WANTED to run HARD!!!

Like I said, you may think I am crazy but it is the truth.

Why do you think most rental G35's feel so fast?!?

 

If it smells like a lemon and is yellow like a lemon..........or duck something or other.... maybe you're right.

 

I've always had the perception that the '03 loaners were faster than my '04. I would wager a guess that the loaners are driven "exuberantly"; maybe that's the ticket !?!

 

I don't want a car I have to drive hard all the time just so it will go like it's supposed to when I want it to, and I don't understand why any manufacturer would build a car like that. When you put the hammer down, the engine should go all out, regardless of how the car has been driven in the past. If the ECU really is pulling out that much power, just because it was driven lightly for a while, then I made a terrible mistake buying this car. I hope it isn't so.

 

I drive my G softly about 95% of the time and that doesn't stop it from running damn strong when needed. I bought the car with 22K miles in January, I've never reset the ECU, and it ran quite well at the track in May. I know you said you timed your runs with a stopwatch, but that's hardly as accurate way of doing things. There are way to many variables. There's no way you can be sure you're hitting the start/stop buttons on the watch right when the run begins and ends. Also, the speedometer is not very accurate at WOT. I know that when I was passing the 1/8 mile trap boxes, my G was only showing 70mph on the speedometer, but the slip said 76-77mph. At WOT, the speedometer needle can't keep up with the true speed especially in the lower gears like 1st and 2nd.

You had also mentioned you had a Z06. Well 99% of the other cars will feel **** slow compared to the Z06 (BTW, I'm jealous). I didn't think my G felt terribly strong either, but the linear power delivery and fat torque is misleading. The G, while feeling quite a bit slower than my old modded 96 Maxima, is only .1 seconds and 1.5mph slower. That's hardly anything.

Reset the ECU and then take it to the track and see what happens. That would allow to figure out if something truely is wrong.

 

Reset the ECU. Wrung it out a bit, tranny seems to shift firmer. Then I measured a 0-60 and a 0-100:

82 degs outside, high humidity, level road, 15 ft elevation

0-60: 7.50 secs
0-100: 17.59 secs

On the 0-100, I gave the car a several tenths head start before starting the timer, so the time is prolly closer to 18.0 secs. That's at least 3 secs slower than it should be. The car is making no power on the top end. This sucks.

 

The only way to document your pain is to get the car on a dyno and see what it does. From what I have seen, a stock 5AT will put down between 204-215 RWHP and about the same TQ. Assuming a 20-22% drivetrain loss on the AT, that puts the 204 right about the 260 crank value Infiniti claims for the 03-04. If your 05 is supposed to be 280, then you can expect a 218-225 RWHP run.

I put down 231 RWHP with the mods I have, and that equates to about 6.3 sec. 0-60 with my stopwatch. To be in the mid-sevens, your power would be way down and that would show on the dyno. Then you take the dyno run data to the dealer and now you have some evidence. But to be honest, you sound like you would be happier with a 6MT, maybe the dealer will have mercy and let you swap if the 5AT dyno is **** poor.

 

I went looking at the G35 determined to get a 6MT--until I drove one. I couldn't stand the shifter placement. I'm used to having my forearm parallel to the ground when shifting, and I had to reach down to the shifter. It felt really awkward. And since I was already giving up 2+ secs against my trade, I decided I could lose another tenth or two and get a 5AT which my wife preferred (she'll drive it too). If the dealer won't give me another car, and can't fix mine, I'll definitely do the dyno test and see what's going on for sure. Then if Infiniti won't/can't fix it, I'm calling a lawyer. Sure wish I'd gone with the GTO instead...

 

Correction. I wish I'd kept my Z06. Delivered with no defects. No problems when I traded it in 3 years and 47,000 miles later. What did I get with my new G35? Tweeter rattle, stuck radio button, audio settings reset themselves on every start-up, advertised power not there, and worse gas mileage. What a fool I was.

 

Johnboy, fwiw, I'm convinced that there is something wrong with your G and I don't buy any of the break-in or ecu adapting explanations. Get your G into a GOOD infiniti service center asap!