This will/should answer your PM & put the info for all to see...
b136,13 shield earth will, somewhere along the lines get an earth, but it will be supplied by the ECU.. so the test to do is with B136 unpluged 13 should not have any continity to ground, of course when you plug B136 into the ECU it will have a circuit to ground no doubt through its noise supression/protection circuitry.
So yea, with 136 unplugged and no continity to ground you have done it right (long as all the correct wires/earths/shield are jointly connected).
B136 12 is one of the earths that goes to ground on the chasis and B136 18 joins it at the same location as does B137 24, if you trace using the V3/4 wiring diagram you will see this. (there is a diagram in note 4 showing this in this thread)
B136,7 is the AFM dedicated earth (i.e. point to point from AFM to ECU) with the plug B136 unplugged it should not have continuity to ground or any other sensor earths... hense the word \'dedicated\' (yes when you plug B136 in it will/should get an earth supllied by the ECU)
B136,9 - crank and cam sensor earth (not the shields) you can solder these two wires together and simply join into pin 9, just dont get the signal and earths mixed up.. i\'d be double checking these sensors and in doing so i\'d be refering to the v3/4 diagram and colours to assist.. so trace and double check: signal wire, earth wires shield wires
so yea, dont worry too much about earthing behaviour once the ECU plugs are plugged in, just make sure its all mint/matches v3/4 wiring with it unplugged
You have to hyper-focus and truely understand whats going on, dont rush, take your time, guessing and hoping for the best dosent work here . You will suss it, its very hard to help out over the interwebz
HINT: if you are 100% sure you have it all right and it still wont fire/run??? pull your plugs and clean them, they foule REAL easy from prior bad starts and crap running
HINT2: for the likes of tracing/distinguishing cam and crank signal & earth wires it does help alot to use an actual under manifold v3/4 loom as the colours make it easier to trace using the v3/4 diagram. in saying that it can be done using the TT loom.