printing issue after replacing nozzle

Hi
I have a prusa i3 !
my nuzzle blocked and I had to replace it with a new one !
its 0.4 mm !
but after replacing It looks extruding more filament.
here is the images before and after replacing.
I didn't change any setting in "Simplify3d" !
does any one have suggestion !?!!

Did you try a different slicer to confirm?
Simplify3D can mess prints up sometimes, in my case it loves to print things without the holes in it.
Why would the new nozzle extrude more?
With a bigger hole you woud actually get less plastic onto the area as the amout of filament going through is less compared to the smaller hole.
Maybe your old nozzle was already partially blocked for quite some and you adjusted the settings to that?
Did you do some calibration prints?

The old nozzle was 0.4 too .
about the calibration I just set the home position and bet calibration with nozzle !
should I do something else ? I use the same gcode file which I used to , without any changing !

Have look here, it is for Slic3r and with that you can get most of the values you need in Simplify3D.
If you just want to stick to Simplify do the same for the calibration as in the Instructable, just with the settings from Simplify.
Start with the basic settings in the "Extruder" settings.
Set the "Nozzle Diameter" to "0.4" and the "Extrusion Multiplier" to "1".
Print a small test cube with fixed outside dimension and wall thicknees, let's say 20 X 20mm in size with 5mm walls.
Measure the outside dimensions of the finnished part (you can stop once enough for a good measurement is printed) as well as the wall thickness.
If it is more you need to reduce the multiplier, if it not enough increase the multiplier.
E.g.: Instead of 20 X 20mm with a 5m wall you measure 20.6mm and 5.1mm for the wall - you set the multiplier to 0.9 and try again.
Repeat until the dimensions match.
Best performed at low to moderate speeds but not at full speed, so go for "High" in "Auto-configure for print quality".
Make sure the temperature is not too high as otherwise such a small part can deform during printing.