Like Mike B said pour a 32 oz of Power Service along with 10-12 oz of MMO or 20 oz of Lucas in your tank and take it on a long hard work out to get the engine hot. This will help to clean the carbon off the injectors. Heck even Cummins has been known to give the same advice for this problem. If you try this first and it does not work then pull the injector but not before you try the PS or Lucas as it could save you some $$.

Good Luck.

 

Here is a step by step with pics.

http://www.tdr1.com/forums/showthrea...place+injector

 

Yes, the nozzles screw out of the body. You need to take a 19 mm wrench and make it about 1/2 as thick as normal. Take a grinder to it. The wrench will then fit on the injector. I had a buddy with a wrench hold one end of the injector while I unscrewed the tip. You could also use a vise. I believe the tip should face upwards when taking it apart, because there are some parts inside that can fall out, but maybe it's the other way around (cant remember). If you're going to clean them, soak the tips in the injector cleaner for a while, then use the toothbrush. I've heard that people can complete the whole process of changing the injectors in 2-3 hours. It took me a lot longer than that my first time. You have to torque and re-torque some things, and it's kind of a pain in the rear to lay over the engine while working on it. Plan on the better part of a day, start early. The satisfaction of doing it yourself is well worth it. Adjust the valves after the injectors are installed.