Is the u13 BB eng. idle stuff different? cause I put it on my de extrudedand match ported int. man. and it's not idling past 500 rpms no mater how I turn the screw. shes boosting fine but just no idle. just liked the metal screw compared to the u.s plastic one. also it was in much better shape. I also swapped the air regulator. did I do a bad thing? thanks in advance.

I put a usdm AAC valve on my BB DET and I'm able to adjust the idle screw and the idle changes as I do that.

Be sure that you disconnect the TPS while adjusting the screw.