GN sputtering around 4,400 rpm

[BUICKGN3]

Actually this past weekend was the first chance I’ve had to work on it.
Installed new ignition module and coil pack and my O2s are back around 750, ( they were in the 500-600 range) the car keeps pulling and 0 KR.
The old coil ohmed out good but I just changed it all. I did find that the last time I put it back together I had the injector harness for the left side pinched between the ignition module bracket and plate. I don’t know if that was affecting it or not but now the car is a lot better but trans still takes a little to long to shift.

 

[dank GN]

Another thing about valve springs most ppl don’t realize is they loose a lot of seat pressure after the first couple heat cycles . And if you installed them and just slapped them in without measuring valve stem hight or valve spring pressure chances are they where super low to begin with . My guess is your valve springs are starting to float around 4K .

 

[GNRick]

I've pretty much cured my sputtering issues by installing an ACDelco module and coil, and turning the alky up to "8" on the little blue knob. Plugs are gapped at .032 ngk UR5, mismatched plug wires for now. Boost goes to 24 psi with old school ATR downpipe and wastegate. 6157 turbo. Translator is set to 4% rich at WOT. LT1 MAF. Valve springs were replaced when the motor was rebuilt around 100k miles ago.