Engine stuttering

[GhostThatSmokes]

I recently went from a DPS turbo (64 ) with a 14cm exhaust housing to a VGT housing to get better bottom end and wider range of performance. We ended up with a stuttering engine, depending on the mechanical controller adjustment the stuttering goes to different rpms. It's worst under light throttle and will disappear under WOT. The truck has honed injectors, #10 fuel plate, DPS exhaust manifold, 4" downtube and exhaust. The P7100 pump is set to factory spec's at 13.5 deg. I'm lost, we can't find any solutions

 

[Signal73]

You might need bigger delivery valves. What HP p-pump do you have?

 

[GhostThatSmokes]

P-7100 stock pump, and it ran smoothly prior to the VGT change, but DPS asserted it wouldn't be the turbo. Had to be fuel problem and suggested leaning out the A/F adjustment

 

[GAmes]

Why would you add fuel and not timing? Gotta give that fuel a bit more time to burn. How much depends on how you use the truck. I would start at 16, then adjust from there.

 

[BigPapa]

suggested leaning out the A/F adjustment

What does this mean?