there is a rod between the throttle assembly and the oil metering pump. When the throttle? or something on the throttle assembly is pulled (rotated), the rod is pulled up, and when released a spring pulls the rod back down to neutral position. Once mine is up, it stays up....is the spring that brings it back down at the throttle assembly or down by the metering pump??

 

That linkage it actuated by the throttle. Once the throttle is returned to idle, the OMP line should be down also.