will pump fine 20 yards or 200,then will slow down to almost nothing,pump cylinders go almost so slow u cant see them move,turn up the volume on remote then it goes all out for a couple strokes then back 2 nothing. any help would be great.

When it's going slow have u unplugged the coil on the stroke limiter to see what happens?

put on a new one,still does it

sounds like one of these problems, you have to catch it when it happens...check your pressure settings at the stroke limiter, what is the pressure at the MG port, should be ~ 50bar, MY port should be 30-32bar, turn the air on the air pressure regulator all the way down, turn on the cp, fwd or rev., and whatch the gauge, it should follow your stroke limiter knob (max on knob - 0bar pressure) and then you need to find out, what are the pressure readings when the problem occurs; we have a candy cane to pump water, sometimes we can simulate p[roblems; is that a Comfort Control you have on the pump?

Try overiding the soft-switch valve(90 deg. valve on front of brain) and see if it makes a difference?

I am having same problem but opposite.  I go good for a few strokes, then it gives me a full stroke on speed 10!  Really bad for the guy on the end hose.  I have no clue what to do.

When That pumpkit overheats or the computer gets told it is overheating the machine will de-stroke all by itself...Im taking for granted that you have comfort control on your machine...check hyd. temp when problem is happining and hyd. pressure...                       Hoper this helps

pumpguy, you're right, both Comfort and Vector will destroke depending on oil temp, but (mainly to finish the job) both control systems will destroke to 50% output, so you should still see 10-11 strokes/min. at this point;

not a real schwing guy but you also need to check for trash in the volume control block also have had this issue before with a putz.