first startup

[Cdc1221]

And she idles smooth, but free revving, she gets to 4500 rpms and falls flat on her ass. Could this be the result of a crack in my header? Or is something else going on

 

[miguelmcv]

If the crack is big and is before the O2 sensor, it will cause the same issue that you have.

 

[cmfd]

depends on where and how bad the leak is becuase it is before the 02 sensor. have you set base timing yet?

 

[Cdc1221]

Mine is a 2g so no need. And its a crack running around the runner right at the flange

 

[miguelmcv]

A crack on that spot will definitely cause some issues, Have you done a boost leak?.

A boost leak can play a little on this.

Make sure you have free leaks and replace your manifold and go from there.

 

[Cdc1221]

Im running a maft on the intake mani so boost leaks wont cause issues unless its in the mani. Guess ill fix the exhaust mani and go from there