In a message dated 1/15/2007 10:21:35 A.M. US Mountain Standard Time, [EMAIL PROTECTED] writes:
Since the air intake is essentially wide open on a diesel (vac governors excluded, but have the same effect), something has to control engine speed. The governor "combines" the engine speed with the accelerator position to determine fuel delivery. As engine speed drops for any given pedal position, the governor weights will drive inwards under the influence of the return springs and rack return spring to rotate the sleeves in the IP to give more fuel delivery. Yes, it does indeed work like a speed control, although it won't change the accelerator position -- the accelerator linkage will over-ride the governor towards more or less fuel. The main effect of the governor is idle and low speed operation, where lots of fuel is needed to get moving, but a large change is speed is not desired. It will also help to maintain speed on the highway, within rather small limits. Needless to say, this isn't quite a simple as that (although not a complex as the gasoline injection pumps!), but what you will get with new bushings is better speed and "throttle" control -- the engine will not "hunt" for speed, for instance, and won't lag or run on when you either press down or lift up the accelerator. Peter, If we are talking pre computer controlled Mercedes diesels, such as the 617 turbo diesel, you are totally wrong! The governer does not have any function between idle and full rpm. The only things that control engine speed are the load, and the position of the fuel rack. Jim Friesen Phoenix AZ 79 300SD, 264 K miles 98 ML 320, 147 K miles