robert19890412

Got my new ls2 402 stroker installed and started. Wont run for more than a few seconds does it need a tune to run? Also car is a 98 corvette.
it has cam that is .612/638 at 112
ls3 heads and intake manifold
ls2 throttle body
42lb injectors
ls2 map sensor and cam sensor

G Atsma

You gave the lift but not the duration, which is actually more important.

robert19890412

Oh read that wrong

274/286 612/638 @112

G Atsma

Hey YOU mentioned the cam. Lift and LSA don't affect how an engine runs NEAR as much as duration.
But as far as starting and dying, it might be VATS staring you in the face. Why, I don't know, but it happens.

G Atsma

That's advertised. Do you know the .050 spec? That's more commonly used nowadays.

robert19890412

G Atsma

224/234. Thank you. Nice lumpy cam!

robert19890412

Is this why it isn't idling?

G Atsma

How low are you setting the idle? It should idle around 800RPM

robert19890412

It idles for maybe 10 seconds throws a p0101 code and stalls. will only restart if i clear the codes.

G Atsma

No, I asked for the idle speed setting.

robert19890412

stock, it hasn't been tuned.

G Atsma

Stock idle is around 500 RPM. That cam won't idle at that speed. You need to tune that engine.

gametech

iTrader: (1)

Stock, with no tune, the change in displacement, the bigger injectors, or the cam would each by themselves keep it from running. Even just the heads, intake, and TB change would make it idle poorly if you had put in on the stock motor. With everything together, I am surprised it even tries to start.

Darth_V8r

iTrader: (4)

Short answer to your original question, yes you need a tune.

Set displacement correctly
Dial in VE tables
Dial in maf
Dial in timing
Raise idle speed
Program all your idle controls
Set correct fuel injector data

That's the short list.