The screw is kinda hard to see... . but do this:
1) With the engine off... . have a cute gal sit in the cab - just tell her to hold the throttle to the floor while you are making a vital adjustment to your fuel injection pump. She'll think you are a genious... and that you trust her to help you with this important mission. :-laf
2) Literally lay on top of your hopefully lukewarm engine so that your face is near the back of the injection pump - with the cute gal holding the pedal to the metal, you will be able to see how the linkage has a little stop which consists of a screw with a 10mm hex head on it, and a 10mm locknut. (**all you need is two 10mm wrenches, but take out all kinds of other tools to make yourself look important!!... vernier calipers are good for this... **) Adjust it out for higher idle speed... . and the opposite for lower idle speed. You won't have to move it much... . probably about a 1/4 turn, if that... . Have the cute gal move the throttle from idle to full throttle if you can't figure out where the screw is... . it will be obvious once you see how it all works, however.
3) Be careful when you dismount from the engine bay - that hood latch has a nasty habit of hitting folks in a not so pleasant area.
4) Make sure all tools (that includes any human appendages) are removed from the engine bay... . and tell the cute gal to get her foot out of the throttle and give it a crank.
5) Squint your eyes and make yourself look important by checking the tachometer and other gauges, go out to the engine and look at that a little too... and say things like: "Hrmmm... . okay... that looks about right. Now rev up the engine a little for me. Okay... let it idle now. Hrmmm... . shut it down please... thank you. "
6) The cute gal should by now be blinded by your mechanical abilites and you'll look like a hero!
7) Repeat steps 1-5 until you get it right... . but keep in mind... . even if it takes several attempts, you can just say that it's a very precise adjustment.
8) Thank the cute gal for her help... . and hope that this proceedure may have helped to 'break the ice' and you may be soon dating her!
Matt