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Ok I have recently gotten back into trains, right now I have these...

Williams "O" Gauge  3 Rail Santa Fe F7 Diesel Locomotives

Lionel 8757 CONRAIL GP9 ENGINE

MTH Premier 20-2146-1EMD

Rail King "O" Scale "Union Pacific" Big Boy Cab No. 4020 With Proto Sounds #30-1129-1

Lionel Missouri Pacific (MOPAC) GP-7 Diesel W/ Light and horn 6-18514

LIONEL POSTWAR O GAUGE 2348 MINNEAPOLIS & ST.LOUIS GP-9 DIESEL

I also just purchased a lionel zw 760a with 2 of the power supplies.  I am having trouble with the engines not wanting to run right with it, the lights won't light up or move at all until it is about 3/4 throttle, I'm on old 3 rail tubular track and I'm seeing where sparks at certain points on the track (maybe dirty?). Nothing else works like horn or bells.. ?? Any info I greatly appreciate!! Cho cho!!