how to clean the fuel injector? i mean not by seaform remove from the car clean it up and put it back.

 

It doesn't seem easy for the weekend mechanic. See link to article below.

http://www.asashop.org/autoinc/sept98/techtotech.htm

 

You really need it to be done by a professional as you can damage the spray pattern. Not something I would try myself and I am pretty handy, swapped motors, etc... You can try RC Engineering, I have used them a few times for my race car and they are great to deal with. You are most likely looking at $24 per injector, and they give you a before and after flow chart with the status of the spray pattern etc. Your car will be down for a week or so though.
Here is the link:
http://www.rceng.com/Fuel-Injector-Cleaning-P43C0.aspx?UserID=2545818&SessionID=qJGk4gIUXLF3n4 s1X{nK

Good luck