Hacking the Bosch injector pump governor

rmattila · Post by **rmattila** » Mon May 07, 2012 2:48 pm

Has anyone any experience on modifying the characteristics of the XUD by changing the governor spring? I'm thinking of changing the spring to a weaker one in order to prevent rpm drop when loading the stationary engine - aiming at a constant velocity around 2000 rpm.

sdelasal · Post by **sdelasal** » Mon May 07, 2012 3:01 pm

I wonder if you could use the cold start speed adjuster - When the wax-stat is cold, the lever gets pulled toward the back of the pump - adjust that to give you 2000RPM. When you want normal idle you simply push the lever to the front of the pump .... simple & might work!

electrokid · Post by **electrokid** » Thu May 10, 2012 12:57 pm

I'd be inclined to put a servo control on the throttle cable.

rmattila · Post by **rmattila** » Thu May 10, 2012 1:22 pm

Changing the two-phase spring package to a normal regular spring used in variable-speed control versions of the pump should in my understanding do the trick, if only the spring constant is correct. Might take a couple of iterations to get it sorted out.