Okay, so ive been killing myself trying to find out why my car is so slow. I have a 2005 G35 Coupe 5at with exhaust and Z-Tube.

Basically, im one of those guys who posts 8 Second 0-60 Sprints. TOTALLY SUCKS! Do you know what its like lining up to a Pontiac G6 GXP and watching him walk away?? Its worse then being stabbed repeatedly by a short knife. At least being stabbed would kill you rather then catching a G6 at the next light and he just points and laughes...

So im asking, all of you, what would you suspect as the reason my G is so slow? Pretend this was your G and please provide input..

Dont gimme the "its an auto" crap, thats just not helpful or funny. Ive changed the spark plugs, installed a new PCV valve, new exhaust(thinking it was kinked or something), cleaned the MAF, did ECU rest, ran her cold and warm with no real difference, no oil consumption, running full synthetic front to back, cleaned the throttle body, and basically prayed to multiple gods hoping for divine intervention... (no fix still hahaha)

2005 G35 Coupe, 18" wheels, 91oct, 5AT, VLSD
Heres what my car does:
-Idle drops to 600RPM-ish, sometimes the bottom part of the needle drops below the 3rd tick on the RPM gauge from 0
-Strong smell of gasoline when i start her from overnight sitting.
-SMALL amount of oil leaks from the bottom(size of a .50 cent coin), looks like its coming from the oil filter. Had it checked by 3 shops and none of them could tell.
One time my car fell flat on its face from a stop light and my throttle body failed. Turned off the car and it went away. Shop cleared the code saying it was throttle body failure but it hasnt happened again, ever.

Thanks for reading all of this, im just really at my whits end with this. I know 0-60 dont mean crap and street racing is stupid. I dont street race ever, sometimes i need to change lanes and Dbags wont let me. Its nice knowing i can pass them but sh!tty knowing i cant.

 

All of the symptoms you listed remind me of my 300zx. I had a 1990 and there was a machine head flaw that year. I sold the dam car and let someone else deal with it. Well that person texted me a picture a month later of the engine completely out of the car lol. Your probably gonna have to get someone to rebuild your engine if you can't figure it out soon. Goodluck

 

There's a lot of factors when running a car at the track, just a few things off the top of my head is reaction time, power to weight ratio, tires, temp of track and etc, altitude blah blah blah.

What diameter piping is your exhaust, inlet/outlet? y pipe or true dual?

 

Reset ECU and start driving more aggressively? lol.

 

^ Yeah you could try the ECU reset by pedal methods... That may help but I wouldn't really count on it since you seem to have done just about everything.. GLwr and post the problem if you ever find it!

 

Not an expert here but fuel filter?? fuel pump?? The smell of gas ususally is a sign of a fuel filter being clogged. any type of oil leak I'm sure causes a loss of pressure which should also cause a lack of power. Shutoffs like you were talking about could be from the MAF sensor going bad. Are you throwing any other codes?
The symptons you are having are issues I had with a different vehicle and the remedies were fixing all of the above. Hope this helps

 

How is the MPG? The strong gas smell indicates a injector o-ring leak

What is the compression test numbers?

How is the a/f ratios?
Plug condition?

 

I think the fuel filter is in the tank in our cars, atleast in my 04 coupe.

 

It sounds like you're doing it all right. Got any bad weight in the rear? How're your launching skills? Do you hold break, give gas, then launch? Do you have VDC totally disabled (yaw sensor cut-out)?

You're not at a really high elevation are you?

My ONLY guess is going to be, 91 octane, you're just not getting the full hp as the engine reduces timing to compensate for knocking (or so I read). I run 93 in NY all the time...which isn't going to make the car last longer, but might let me keep aggressive ECU mapping a little more often.

 

Dyno the car.

How are you recording your 0-60?

 

Great post. Sounds like the OP's issues are car related, not driver related.

 

before you do anything crazy like tear down your engine i think the best move you can make is to have the car dyno'd and when they do it make sure that your air fuel ratio is recorded. also you should keep in mind that a 6mt is listed as doing 0-60 at 5.4 with a pro driver, with a normal person probably closer to 6 and as much as u probably dont want to hear it a 5AT will be probably 7 this car is alot heavier than it should be and AT's dont do as good with weight. if the dyno numbers are alright then it may just be time to put in for some more mods. also a base model G6 is listed as 0.3 faster than a 6MT in a quarter mile so even though its a ****box it probably weighs 800 pounds less

 

What would I do?

I'd wait about 30,000 miles, then offer to race my friend. By then his Pontiac will have suffered a major breakdown, and since Pontiacs weren't good enough cars to survive even a government bailout of GM, there won't be any parts to fix it.

I'd just cruise over to my friend's house in my 8-second G and offer to race his Pontiac that's sitting on cinderblocks in his front yard.

That's what I'd do.

 

Instead of praying to multiple gods.. pray to one God.

 

what are you smoking