Vaccum or Fuel pressure?

[Dunny]

Finally done with tune up. 3 bad coils, harmonic balancer replaced (thank you all for the info), kenne bell pulley replaced (upper and lower), scarred up knuckles replacing spark plugs (THAT ONE!!!), new CAT CONVERT with straight exhaust going out the back ( yes I covered the side exhaust slot). Runs great until I hit HIGH RPMS. If I floor it for about .07 sec my L sputters then kicks in. Air/ fuel ratio 11-12-13ish flooring it. A buddy says his L does the same thing on the stock set up and his vacuum hose is flat. barely anything flowing through. I do plan to buy a hand held tuner. Once I do accurate research. Right now Diablo has my attention.

So....fuel issue....vacuum issue...or something I'm not tracking?

Thanks in advance Fam!!!

 

[ViperRed91GT]

So do you not have a tune right now?

 

[Dunny]

I have an old tune from 2009ish after the major upgrades

 

[Dusten]

To many variables to determine issue. If your afr is in the 13s get out of it. If a boosted vehicle is missing under boost, get out.

You need too monitor and log afr and monitor fuel pressure.

 

[Dusten]

Also, what plugs? What pullies? What gap on plugs?