ps2 f-3 cat engine cuts in and out while running.

Item number please.

I'd be inclined to remove the shell and make sure all plugs are fully seated.

I have the same engine in B&O and it does the same thing at higher (above 20mph) speeds. Apparently it is a processor fault and it would require new boards (or just one of the two boards) to fix per a post on the forum some months back. 

Might be better to find a new PS3 version and swap the shells. 

Don't take my word for it, I'm just relaying what was told to me. I'd recommend having someone check it out just in case it is something else or even to see what your options are. My engine runs fine at slow speeds (which I usually run anyway) and haven't been able to reproduce the issue in conventional. 

Until it really becomes inoperable or "screwy" I'll run it. When things go south, I may find another to swap shells, put a Williams horn/bell board in it, etc. I'm holding out hope they'll reissue one in PS3 also!

that's why I try to buy all ps3 engines.

I find all 22 of my 3-volt PS2 locos to be rock solid.

Does this version have the separate rectifier wired into the power supply with the motor diode also heat sunk to the chassis or is this a standard PS-2 3V install?

When it stops does it restart with sounds just no motion?

I am pretty sure I can isolate this down.  I have seen the motor circuit flyback diode fail causing this type of issue. 

Obviously the first checks are that AC pickup power is making it to the board.  I realize you soldered the wires, but broken wires under heat shrink at the truck, dirty wheels, bad pickups (rollers or slides) can cause all this too.   G