Hi,

I have a question, I have a friend who has an 03 5AT Touring ed 350Z and it stalls out and dies upon start up. Basically here is what happens, when you turn the key, the car cranks and starts very smoothly. It has the momentary increase in RPMs but after just a few seconds, it starts to sputter and then dies out. It will start back up and do the same thing.

The car is not throwing any codes. I replaced the MAF and it did the same thing. It has an AEM intake and Stillen exhaust as the only mods. The battery is new, as are the terminals. The strangest part is that there are no codes, it starts very smoothly and quickly, no hesitation and no misfire, it just won't stay running. If you give it gas, it makes a puffing pop sound in the intake and then dies.

I have searched and have seen a lot of discussion about cam and crankshaft sensors, TPS, MAF, throttle body, etc, but just wanted to see what a general consensus would be on the next step we should take. Also there are no vacuum leaks.

Thanks in advance

 

Wow, could be a lot of things.You don't state mileage, and the if the electronics you mentioned were bad, he "should" get a code.

Remember, you really only need consistent fuel, spark and air. Perhaps the air filter is dirty/needs to be cleaned/replaced. Make sure all intake connections are snug. For fuel you might try cranking it for a bit, and pull a spark plug. See if it smells of fuel. For spark auto stores sell inline spark checkers. You place it between the wire (or in this case coilpack), and spark plug. Crank the engine, see if it lights up. Or simply pull a coilpack and let it ground safely to something ferrous. (Easier at night to observe spark).
If the car is over 100k and was never tuned after intake/exhaust it's possible that the cats have become blocked enough to prevent running, but technically that should throw a code.
You do not state if the problem was gradual or overnight. When trouble-shooting, always ask yourself "What has changed since it ran well?"
gl.

 

the problem was pretty much overnight, the car has 160k. What it was doing is this, it started up, idled pretty smooth, if you drove it somewhere, turned it off and let it sit for a few minutes and then came back to start it, then it would idle rough and bog down unless you pushed the throttle and then it would clear up. Then one day it started doing this. I thought maybe o2 sensor for the earlier problem of bogging down and then this started.

 

What kind of code reader are you using? I've seen a few instances where a generic code reader had nothing, but when I used my UpRev Cipher software there were codes in not only the ECM section, but also ABS and BCM as well.

 

Yea this sounds like a job for a shop to chase down.

That could be a whole head ache of a search.

Somethings like that should just be given to a reputable shop to let them run a proper diagnostic. They'll probably find it with in an hour or two, where it might take you months to hunt down.