E unit works intermittently

It sounds like your problem is in the solenoid portion of the e-unit. Can you determine if the plunger is not lifting when power is applied, or if it is not dropping when the power in turned off?  Solenoid plungers not dropping when the power is turned off can be a problem. Lionel redesigned the plunger with a recessed conical top. This redesign may have been an effort to get the plunger to drop more reliability.  Another thing that can be checked it if the plunger has become magnetized.  

Other people have described rebending the hook on the plunger to get the e-unit to operate better. Before trying this look very closely at the interface between the hook and the teeth on the drum to see if bending the hook could improve the operation.

As David mentioned the hook can be a problem, also look to see if it has any burrs. I've also encountered problems where the pin protrudes out the side. Some cases it's a tad too long and will hang slightly on the motor frame.

Need to make sure there is no binding or hanging of the plunger that is connected to that hook.  You should be able to flip it over back and forth and it slides easy back and forth never hanging up.  If you put any lube in there that can gum it up.  I guess you can also check to see if it has become magnitized as well.  Usually for mine if it is hanging it just needs some tuner cleaner.  IF you are skipping a position, like John said, may be the hook or the fingers.  IF the fingers are not landing in the correct spacial location, they may end up on the edfge or just past the copper pad on the drum.  So if you rebent them or if they are new you want to try and visuallize exactly where they are landing andwhere the drum turns to and stops.  Adjusting the end of the hook and sometimes adjust that stopping point to help but you need to be careful or you can get far out of whack lol.  Good luck!

I included some discussion about the E unit in these two videos, you'll have to skip to find it...

Skip to about 26 min mark for E unit removal

https://www.youtube.com/watch?v=ZhDupCili1E

and about 8:48 for putting the drum back in the E unit in this one.

https://www.youtube.com/watch?...cEsZbbfps&t=496s

Understand if you have worked on it already you know your way around but you might catch something helpful.

I read your post again, could be couple of other things as well.  CHeck your roller pick up.  IF it is dirty or if the roller holes are elongated, you can get sporatic conductivity.  Be unscrupulous and clean the crap out of that bugger. The other, sometimes if you did not give it enough voltage on the previous sequence, it will stay in forward and then as you run it and raise voltage you will get to that threshold and the solenoid will lift and cycle.  Keep in mind, you will have slightly variing voltage around your track even with drops do to dirt or distance.  Might be worth seeing if it is due to that.  Usually that can be improved on with cleaning etc.  IT can be annoying.

Thanks you all for the great info.  I will keep all these things in mind as I try and complete this project. I will let you know what I find out!  Your help is greatly appreciated! 

When I opened the engine back up I noticed that when I put 12 volts of power to each post of the e unit it cycled fine. The plunger didn't hang up, and the paw was able to turn the drum perfectly every time.  Could it be a soldering issue that is causing the intermittent cycling when power is interrupted while running it on the track (track is clean and has strong voltage through out the loop)?  Just to make sure I have it wired correctly, I have the black wire soldered into the motor field and the green wire soldered into the opposite post.  Like I said the engine runs great in the direction it is in, it just has trouble cycling from forward- to neutral- to reverse.  Also, while running it will intermittently go from the direction it is in to neutral.  Thanks for your help!

Almost sounds like something is grounding out intermittently like when rolling through a switch.

It sounds like a bad connection to the E unit.  The E unit is losing power intermittently causing it to cycle. This can be one of a few things:

1. Does the engine have slide shoes or pick up rollers?  Slide shoes must be really clean and can lose power over switches.

2. The hot wire coming from the pick up rollers to the E unit could have a cold solder joint.  Re-check that connection.

3. The E Unit switch (lever) could be loose.  The E unit switch completes the circuit to ground to keep the coil energized.  Its its loose, the movement of the engine will caused it to lose power.  The lever is press riveted on.  The lever should be fairly tight.

What is the condition of all your wiring insulation? Have you inspected it? Have you replaced any or all? Have you placed any sleeves over the original insulation? Reads as if you are getting an intermittent short in the power feed somewhere, most likely from the pick up collector wire. Don’t give up, I know this can get frustrating. However this is the beauty of prewar trains, their simplicity.

CJ, you say it's a 260e. Circa what year? Regular eunits went in around 1934, so is the problem the eunit or does it have a switch on the back of the cab....?

Could it be a soldering issue that is causing theintermittent cycling when power is interrupted while running it on the track (track is clean and has strong voltage through out the loop)?

Your statement - ABOVE - that power is interrupted while running it on the Track, makes me believe the E-Unit is functioning as it is supposed to. E-Units are meant to cycle with each power interruption.

I think you need to address what is causing the power to be interrupted.

@John H. Shetler posted:

CJ, you say it's a 260e. Circa what year? Regular eunits went in around 1934, so is the problem the eunit or does it have a switch on the back of the cab....?

John earlier CJ indicated that he rebuilt the e unit with a new drum and both sets of contact fingers.

I have changed most of the wiring, but not all.  It may be the wire that leads to the rollers.  I did clean the rollers.  I will change the wire leading to the rollers and see if that solves the problem. Thanks!

@Rich Wiemann posted:

John earlier CJ indicated that he rebuilt the e unit with a new drum and both sets of contact fingers.

Right, I was simply trying to get the point across it may not be the eunit. If there's a problem somewhere else such as the cab switch? Who knows, it could be the roller tab of the pick up rising up over uneven track and interrupting the power or as Dennis mentioned the drum timing. The last batch of repro drums I got, there was a problem with the copper not being installed correctly. Multiple problems surface sometimes.

John, sorry I missed your earlier post.  The e unit is the old style with a switch that is wired to the e unit.  I will probably change those wires to, but I think the wire leading to the collector rollers is the problem.  I will be sure to post my findings.  Thanks to everyone for your help!  I'm glad this resource is available.  I've learned so much over the years!!

@C.J. How about some pictures of your e unit and motor showing your wiring? Pictures always help with remote diagnostics.

Here is a picture of the back of the e unit.  I will replace the rest of the wiring when I have time.  I'm assuming the only way to get to the wire to the collector is to pull the wheels.  If anyone has a better way let me know.  Thanks.

@C.J. thanks for the picture. Looks like the insulation is frayed and missing on the highlighted black wire next to the motor side frame.

For the pick up wire I would unsolder it from the e unit end and try to snake a sleeve of heat shrink tubing over the wire down to the collector pickup if you can.

After reading what John said about the switch I agree with him. Awhile back mine was moving slightly causing engine to stop.

OK, great!  That sounds much easier than what I was thinking.  Thanks!