pump adjustments?

[Black dawg]

on a customer pickup I turned the afc diaphram 90, adjusted the spring, and the pre boost fuel. He is telling me now that his governed rpm is lower. truck will only go 70 instead of 80. do these adjustments affect the gov? the truck does have more power.

 

[rebel_horseman]

Depending on what spring you're referring to, those adjustments should have no effect on governed engine speed. Sounds like a different problem. I'm guessing the spring you're talking about is the red and green spring under the AFC diaphragm; if so all it does is preloads the diaphragm and causes it to return to normal position.

 

[MIDNIGHT RIDER]

on a customer pickup I turned the afc diaphram 90, adjusted the spring, and the pre boost fuel. He is telling me now that his governed rpm is lower. truck will only go 70 instead of 80. do these adjustments affect the gov? the truck does have more power.

Did you permanently mark the orientation of the diaphragm prior to moving it ??

Always PERMANENTLY mark both the diaphragm and AFC housing with alignment marks denoting factory stock position, thus you always know where you have moved it and can go back if desired.

If not, pull the diaphragm/fuel-cone and look for the wear mark that the fuel-pin has worn into it over the years and line that up with the front of the engine; that will put you back to where you started.


Did you pull the cone and see where it's deepest eccentric was oriented ??