[GTR--J]

I have had a new Nissan long block installed recently and it has a air leak because it idles @ 1600 rpm.All the vacuum lines have been zip-tied so it narrows down my search for the vacuum leak.This is on my list of things to fix but my first concern is when the car idles @ 1100 rpm and under load driving,you can feel the engine hesitate or shudder on each cylinder about every second.Is this fuel or timng related?

 

[langerdan]

if this has been a problem imediately after changing block i would definately lean towards an air leak,pipe off, plenum gasket etc there are so many pipes down there it could be quite easy to over look somthing on an engine job if this occured a couple of days/weeks after completion it could just be coinceidental and maybe a stuffed afm or somthing