Power loss under hard acceleration
 

I have a 2003 touring 350z and recently have had some issues. Under hard acceleration the ABS, Brake, VDC, and Slip lights all come on and all power is lost (mostly in second or third gear) This first happened a couple of weeks a ago, so I did a little research on google and came across some a post from another forum I believe that said to check the brake fluid and add some to the max fill mark. I did this and the problem went away. Today the problem came back, so I immediately checked the brake fluid and it was fine. I am not sure what is causing this problem and I really need some answers. Other things I have noticed recently whether it is connected to this issue or not is the volt meter will move from about 13 to 15 or 16 while under acceleration. The dash lights will pulse and dim just a bit when the volts go up. This problem doesn't happen at a particular rpm, it is rather random and even if all the warning lights do not come on under hard acceleration the car will feel less powerful almost like I am backing off the pedal when I am not. Any ideas as what could be going on? Thanks

I forgot to add that I reset the ecu last night and I still have this problem

go to pep boys and have codes read..

also.. do you possibly have NON NISSAN tailights on your car? If so, theres your problem, I kid you not.

There is no check engine light on, and I have factory tailights.

thre will still be stored codes usually..

is your car equiped w VDC? what are your tires sizes.. larger/taller tire in back id hope?

Okay I understand. The car is equipped with VDC and the problem occurs even if VDC is turned off. As for tires 225/45/18 up front and 245/45/18 in the back. All tired are relatively new hankook Ventus evo v12's.

well weve certainly eliminated the usual culprits, i am at a loss so far, but now w these out of the way, im sure other posters may be able to further assist. :(

Thanks for the input, I will try to get it scanned tonigt and see if that gives me anythig.

Just had it scanned and no codes. Could too much brake fluid be a problem it looks like both reservoirs are just above the max line. Could that be an issue?

If my lights were dimming, first thing i would check would be to get my alternator tested...or possibly coil pack? (although more rare). How many miles?

65,000 miles on the clock. The dimming dash lights were not extremely noticeable but it was happening and it seemed to correlate with the volt gauge spiking.

In my experiences, volt gauge spiking can either be: bad connection at the alternator, bad alternator, bad coilpack(s), or just a bad gauge but probably not.

Just had the Alternator, battery, and starter tested and they all passed. Another thing I noticed recently is sometimes while changing gears the battery light and brake light will flash just slightly.

If the battery light is coming on it either means you're pulling voltage from the battery for a second instead of the alternator, check all the connections and fusible links, or it's close to stalling for some reason.

The battery light and brake just faintly come on when shifting, only seems to happen a few times when I first drive the car after start up. The interior lights, and parking lights pulse at idle and seems to pulse faster when the engine is revved and the volt gauge spikes

My point is, if that light comes on electricity is flowing WRONG direction, problem is within charging system

Check all your connections, including grounds. A bad ground could be causing all of these issues.

I may sound stupid, but I Do t even know where to begin checking grounds.

Probably a long shot but check to make sure your A/C amp (white box behind your shifter, underneath your stereo) connection is secure. Even though I don't think this has anything to do with power loss, it has been know to cause emergency lights to illuminate. Do you have an aftermarket stereo?

I will have to check that box. I have an aftermarket stereo, it came installed when I bought the car. The speakers have been making a humming noise which changes pitch with the speed of the engine, if that has anything to do with the problem