Problem with spectrum 4-4-0. I need some advice. Please read.

[Balevre]

I have 2 spectrum 4-4-0 trains. They are both brand new and I am using themin my dcc layout using a MRC handset. I wanted to use them together to doublehead trains. One of the spectrums runs perfect and as soon as I give it speed step one, it begins to move, perfectly smooth. The other spectrum which is the same train as the other does not run so well. In fact, it does not begin to move until I apply a speed step higher than 8. So speed steps 1-7 only cause the train to make noise and jerk a little with no normal train movement. ( it only begins to jerk within speed steps 5-7) I have done some research and thought that the motor of the one train just needed to be broken in, so I have spent most of last night breaking it in and the train still will not respond unless I apply a speed step higher than 8. I have checked the CVs and have concluded they are all set correctly and I am still have this problem with the train not moving until speed step 8 or higher. Normally I would conclude that the motors are just not the same, however I have 2 other spectrum products (A dash 8 and a 45 ton switcher) and they both act exactly the same as the one 4-4-0 and will not respond with movement but only noise until speed step 8 or higher I have also spent time breaking them in. I also have another bachmann dcc equiped train not a spectrum product and it runs smooth as can be from speed step 1-28. So please someone tell me why these trains do not run unless speed step 8 or higher is given. I can not seem to figure this out. Any advice is welcomed.

Thanks in advance!!!

[GN.2-6-8-0]

You state you checked the cvs but are the speed steps 28/128 set the same on both,also did you look at the speed curves on bothengines?

[Balevre]

You state you checked the cvs but are the speed steps 28/128 set the same on both,also did you look at the speed curves on bothengines?

I am relatively new to DCC how would I check to see of 28 and 128 are set the same? Also I can not find the speed curves. Do you know where I could obtain them?

[GN.2-6-8-0]

Belevre
Do you have Decoder pro from JMRI set up for programming on you PC? you'll need this and somebody with more programming knowledge than i have,though there are many here to help you might also try locating a nearby model railroad club running DCC for help.

[drsager]

Which MRC handheld are you using?  If it is the Prodigy Express then there's not much you can do in the way of troubleshooting.  If you have the Prodigy Advanced 2 *squared* (PA2) then it has the capability to set up a programming track.  The programming track will let you read the various CV values.  Check out this link to MRC's website for some additional documentation on the PA2 (there's links to PDF's at the bottom of the page):  http://www.modelrec.com/search/product-view.asp?ID=7735

Personally I would look at the starting voltage.  It could simply be that the way the motors were wound that they need more (or less) voltage to get them turning.  My Spectrum 2-8-0 needed to have this setting adjusted in order to get it to start at step #1.  As GN.2 pointed out, you may not be able to have this particular locomotive running using 128 speed steps (or even 28).  There should be a Speed / Spd Step button on the bottom left of the handheld.  Pressing it shows the current speed step setting.  If you press it again it will go to the next setting (cycling through 14 / 28 / 128).  Press the Enter key when the one you want is displayed (and don't forget to unplug the handheld so it saves your setting for that locomotive).  Each locomotive can have its own speed step setting, so you may need to repeat this process (as well as setting it again if you delete the locomotive's address from the handheld).

Another thing to check would be to make sure there's nothing binding on the locomotive.  While these units are belt-driven, they are also designed so the belts do not slip.  Any resistance could prevent the motor from turning at slow speeds.  You mentioned similar behavior with other locomotives - just because they are diesels / direct drive doesn't mean they cannot be binding.  Mass production does not guarantee consistent quality / performance.

If the performance is that bad you may want to contact Bachmann's service department to see if they would be willing to swap out the motor (as it doesn't sound like a decoder issue).  The lifetime guarantee is one of the wonderful things with the Spectrum units (although to be honest I've never needed to use it).

You may also want to check out the MRC-DCC forum on Yahoo! Groups.  There are some folks there that have quite a bit of knowledge when it comes to decoders (of any kind) and how to get them to work well with the MRC controllers.

[wjstix]

Two engines, even the same model by the same maker, normally don't run exactly the same.  You can program the slower-starting engine to start moving at speed step 1 by increasing the amount in CV2. It's probably set to 0, try changing it to say 5 and see if that makes it start faster. Then adjust the numbers up and down until both engines start at the same time. You can also check CV3 re start momentum, if that is too high it might be delaying the engine from starting right away.