I've been studying a cut-away pic of a P-pump and I've got a question. I have an engineering background so stupid s h I t like this makes me wonder.

The stock (and some aftermarket) fuel plates have a "sawtooth" profile and I'm wondering why. The plate is in a fixed location and is contacted by the governor follower. I can't tell if the follower moves up and down during normal operation to engage different locations on the fuel plate. If the follower doesn't move, why would a sawtooth profile be necessary? The follower would contact the plate at the same location all the time unless the locations were physically changed. Just wondering

 

Good question, I'm not very familiar on how the whole thing works. But the plate can be moved to different locations.

 

It looks to me like the follower has an adjustment screw to change the vertical position of the point where it would contact the plate. From the angle of the cut away picture, I can't tell if the governor has the ability to move the follower up and down engaging different areas of the profile on the plate. Cummins may have wanted one plate for numerous applications and the technician adjusted the plate position and the follower position based on a particular application. If the follower moves up and down based on governor input then that would make sense too. I'll try to figure out how to post a picture.

 

Picture test



P pump cut-away

 

The gov arm moves forward and back and also up and down depending on rpm.

 

Thanks 94. That makes sense but from the cut-away there's no way to tell if the arm moves up and down. I just figured it was on a fixed shaft. There's a lot of stuff going on in the AFC and governor housing...a true testament to Cummins engineers!

 

Or Bosch engineers, as the case may be.

 

JBear...yeah, I realized Bosch after I posted...duh!