Goran (dieselmeken) shares quite a bit of good info. Really nice guy.
The last pressure he checks confused me at first, but with some thought the pintle lift at idle is not full up to the travel stop, meaning that the hat shaped piece only moves a fraction of its travel. If that spring had variance from the others that you would otherwise be unable to see with the lockout piece, then the pintle lift and therefore the amount of fuel injected would vary, lacking the "idle smooth running correction" feature of the EDC 15 controlled pump.
All the time learning new things.
Is he a TDIclub guy?
I think that you would be safe in assuming that if your pilot, and main pressures are good, your idle should be good aswell. Right..? I guess if you want to be really precise you could check it, but you cant adjust idle pressure without changing main pressure as they both operate on the same spring ( tested with the lift pin from inside the main spring removed )
That video was awesome.
So to make it a single stage, what exactly did you and you guys do to the hat shaped piece? I am a little fuzzy on what you guys do to that piece.
From left to right shows the sequence of event ( closed, pilot, main ) The hat we're talking about is the little orange piece on top of the nozzle and needle. Pay attention to the space in between the hat, and the nozzle. Injector one there isn't enough fuel pressure to overcome spring pressure so the needle stays down ( closed ). Injector two, fuel pressure rises to the point at which the pilot spring ( skinny spring at the top ) pressure is overcome, needle lifts, nozzle opens, fuel flows, pressure drops, needle drops, closing the nozzle. ( pilot ) The third injector shows a further increase in fuel pressure overcoming pilot and main spring pressures simultaneously, needle lifts, nozzle opens, fuel flows, pressure drops, needle drops, nozzle closes ( main )
Now the problem; how to test the main? If fuel pressure drops once the needle lifts on pilot, how can we increase the pressure enough to operate the main event? Disable the pilot. This is achieved by eliminating needle lift with out hat lift ( little orange piece ). If you look closely at the side of the hat which faces the nozzle you will see a raised ring around the perimeter of the face. The injector pictures show this as a space in between the nozzle and the hat with the pilot lift pin coming down through the center. Remove the the raised ring from a
SPARE hat
( if you remove this ring from any or all of the injectors you intend on setting up for service, you will end up creating single stage injectors ) There are lots of different methods of removing this ring. I used a coarse/fine sharpening stone with water to lap the hat down to dimension using a figure eight pattern, rotating the hat a 1/4 turn or so every couple rotations to ensure am even lap. As JFetting said at the beginning, be very careful how much material you remove tenths ( 0.0001") count, check your progress as you go, lap to much, and your pop test will yield inaccurate results.
Check this thread out too
http://forums.tdiclub.com/showthread.php?t=12460
This will have been an unnecessary explanation for a lot of you, but it was also intended for those who don't know
)
