If you can find time in your busy travels would you please explain Pilot Injection, I did a search and found a bunch of guessing.


1-- Whats it's purpose


2-- when do we here it


3-- Do we need it


Thank you SIR


Genohttp://www.dieselplace.com/forum/smileys/Hug.gif

I'm not Eric but I'll try.


1- It gives a small shot of fuel that starts combustion just before the main injection that makes the power. This makes the combustion process more gradual and takes away the pressure spike that normally causes diesel clatter. This is part of the reason the duramax is so quiet.


2- You hear it any time the engine is below around 2500 RPM. When the engine is above 2500 RPM you will hear it getting louder. This is because there is not enough time in the cycle to add the pilot injection.


3- Yes if you want your truck to be quiet at idle and normal driving circumstances. Pilot injection also aids in low temperature starting. Edited by: Max Power

not much I can add really to Tony's comments.


That about hits it.


Thanks Tonyhttp://www.dieselplace.com/forum/smileys/Big Smile.gif

Hmm...


I thought I'd read, and seen posted here somewhere, that the pilot injection is turned of because of emission compliance?


I had originally thought it was a timing thing as well, but maybe the timing problem is what contributes to higher emissions above a certain RPM?

Pilot injection can reduce the NOx emissions because of the lowered peak combustion temperatures. Edited by: Max Power