I was and still are so happy with my recently bought P2K U30B that I run on my DC controlled
layout that I went to my LHS and added the P2K SW8 QSI equipped switcher to my roster. The U30B is a smooth runner but the SW87 is everything but. Both in RTC and STC throttle mode it runs and stops, runs again and stops again, runs again and stops again etc. when I apply current directly to the copper contact strip the motor/sound runs without interruption so I deducted that the problem must be in the current transfer from the wheel/axle set to the contact strip. I tried crimping the axle hole in the contact strip for a tighter fit but that didn’t work. By the way, the track and wheels are septically clean. So, now my question is: did anyone ever experience the same with a P2K QSI equipped and DC controlled locomotive and did he find a way to solve the problem?
I run mine on my DCC-equipped layout. If yours is the same model, it has traction tires like mine. They gave up all hope of putting enough weight in one of these when they added the decoder and speaker, so they provided the rubber traction tires on 1 axle to give it the ability to pull more than a few cars.
The trouble is, you’re down to 3 axles for exectrical contact. Mine works pretty well most of the time, but I still have to give it the occasional nudge when I’m unlucky enough to hit 3 dead spots at once.
If you can identify certain point on your layout where it always runs well, and others where it runs poorly, then you should re-check your trackwork and connections. On the other hand, if the problems are truly random, then you should check the wiring inside the engine and see if one of the power leads from the trucks has come loose.
I’ve the same switcher but it is DCC. Like MisterBeasley mine had the ole traction tires and just loved to stall at turnouts mostly. I replaced the traction tire with NWSL #37191-4 40" HO Nickel-Silver wheels ( these are half axle and fit perfect to the gear hub ). Doing this will however decrease the pulling power but it will go thru turnouts at 1 scale mph ( According to the engineer…F10 with DCC ) with no stalls. I push & pull up to six 50’ box cars on flat track with no problem. Doubt if you want to try any hills though.
I have the same diesel. It moved well between turnouts, but it stalled on all of them. I thought it was a pickup problem and that the pickups were too close together for the tunouts’ dead frogs. I was wrong. The traction tires, as stated above, were the culprits. I called Walthers and said I was having problems. The nice gentleman offered some tips to improve performance, but he also offered to send me a replacement axle with metal tires for nothing. I accepted, and even changed it myself…quite an achievement for someone with my talents.
The trouble you are having is 99.9% going to go away once you swap out that traction tire. I still have no trouble shoving four heavyweight cars from Walthers around my yard with it.
Note: I read recently that Walthers has stopped being generous about replacing those axles. You are likely to have to pay by now…sorry.
Thanks for your reactions. One of the first thinhs I did was replace the traction tire wheels but that did not help at all. There’s not a certain stretch of track where it runs well or where the on/off running occurs. I checked the leads from the current pickup strips to the decoder but they are ok. I think I have exhausted all possibilities except a faulty decoder and that can only be found out by replacing it.
I now realize that it was a stupid deduction to blame a faulty decoder for the running problems. Everything ran flawlessly when I connected the current directly to the copper collector so it could never be the decoder. Never one to give up easily I kept on thinking and eliminating possible causes and sincethe problem had to be the current transfer from the wheels to the collector there was one possible cause left: corroded axle holes in the copper collector. I cleaned the holes being carefull not to widen them and behold the locomotive ran without the slightest hitch. It must have been on the LHS shelf for quite a long time for the corrosion to develop that much that it interfered with smooth operation.