I got my second P2K GP38-2 this morning and installed the couplers and broke it in. I hooked the two locos (They are idenical twins) together and they pull great on flat ground and going up my 2.5% grade. Now my problem...going down hill the locos will speed up then slow down to nearly a dead stop then pick up speed then slow down again. This happens until the locos reach the bottom of the incline.
I am running DC in HO scale pulling 22 freight cars, Going down hill the voltage is running about 7,5 volts and when the locos slow the voltage drops to about 5 volts.
I know that it is not in the track, I have a metal Model Power F7 that does not do it at all. Pulling one of the P2K's will do it some but not as bad as when I double head them. I am running an Athearn power pack that came a train set, it has been a good power pack. It seems as though the cars are trying to push the locos until the locos slow down the cars then will speed up again.
Any suggestions as to what is causing it to do this and what to do to correct the problem? Thanks, Mike