is the frontmost coil on my '84 GSL the leading coil?
what about those designations L1 L2 do they really tell u which is which or can they sometimes be wrong? I'm having a tough time with my ignition.

 

In the shop manual under the Engine control schematic I found that on 84&85's the leading coil has a yellowwire with a blue stripe. the trailing coils has yellowwire with a green stripe. On my 85 gsl-se fuel injected 13b eng, the lead coil is closer to the cockpit. the trailing coil is closer to the front of the car. As for L and T that is accurate if your refering to the distrubitor and the plug wires . There is also L and T on the side of the engine block. so L1 is front bottom, T1` is front top. L2 is rear bottom, T2 is rear top. Hope this is helpful.

 

I had my wires like that at first. But wasnt sure, and had swapped them. Car turned over and started alot easier when i had the wires " Leading on top, and trailing on bottom" I have an 85 gs (( 12a ))

 

I was thinking the same thing when I first took a look under my hood... But all three of the manuals I own including the shop manual read:
T1 T2
L1 L2

With an arrow pointing left that reads FRONT.

Who knows... might have been some Toyo Kogyo engineer wanting to mess with everybodies head.

 

Front rotor is #1 normally... but if you transpose the plug wires AND the coil wires (primary and secondary) you'll still run correctly. This is because the front and rear rotors are 180* out-of-phase to each other, & so the distributor rotor is symmetrical. Only the vacuum advances really need to be 'the right way'.

On the SA's, the coil primary wires are long enough that you can wire them backwards, if you're not paying attention. So which coil is lead and which is trail depends entirely on how they are wired, not on their physical position. Only way to be sure is to check the wire colors.

 

Which color would mean what for the wires?

 

On my 83 the wiring from my coils is front most (nearest the head light) is trailing next is leading.
@DD, that's a new piece of info for me, always learn something new when you make a post.

 

May depend on the year of the car; on an 80, Yellow with Green stripe is Trailing; Blue with a Yellow stripe is Leading. On a 79, Trailing is Yellow/Red.

On SA's, the Tach line goes to Leading, as well; on FB's it goes to Trailing.