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Discussion Starter #1
Can anyone tell me how to check coil modules, I'm not sure whats going on inside them electrically, so not sure what would constitute 'good' or 'toast'. I'm having misfire probs on my TS and I'm having to look into the ignition system a bit closer than just caps rotors leads and plugs. I know they arent too expensive to buy, but I'd rather 1-not buy them for no reason and 2-learn how to test them properly to further my knowledge! everyday's a school day haha!:D
 

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the part was used in just about everything in the time. when mine went bad I got one off a VW or BMW at the junkyard. but at the time I goggled and found the circuit in side after a link or 2. but the short answer is there is a hall switch in the dizzy. so a low current square wave goes into the hall-amp where it buffers and goes to a hi-current transistor. it also has a max coil current cut off (some times called dwell but it is not dwell) it is just a constant current circuit. there is also a buffered output that is not used at all on the v6 for ether l-junk or the tach. but the TS might use it?
 

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Discussion Starter #3
Thanks!

PS, Twinspark gets it's tach signal direct from the -ve post on the coil
 

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That is the same as the V6. I do know when I put in the VEMS I drive the tach from the ECU 12V square wave. and the tach reads 100% all the time. When it was driven off the coil it seem to be all over the place. So I am guessing if the tach was wired to the module out it would read 100% and not all over too. but that is just a guess.
But I think the tack likes a nice 12V square wave over a 300V ringing chirp that comes out of the coil as it flysback. but it looks like alfas wiring is very split. the ECU wiring and the car wiring. And the coil wiring. With almost nothing touching.
So things are feed off the coil and not off some nice clean signal that is there.

I think most if not all of the ecus also have a output for the tach. the hall-amp also has one. but tach use the dirty HV of the coil. as well as the l-junk.
The tach should have been feed off the ECU or the hall-amp. The ECU should have been feed off the hall-amp or directly from the hall.
but alfa is alfa and did it the worst way possible for each part.
Some how I see 3 different guys working on this not talking to each other.
The coil/spark guy
The injection guy.
And the instrument guy.
and each one making it hard for the others.
 

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Discussion Starter #5
haha! bitter?
we love them really
 

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No not bitter but it is one of the things you look at and have to wonder what the hell went on. And I bet there is a real good story behind it.
And it it not just alfa every once in a while you run across some thing like this. And the only thing that comes to mind is some sort of fighting on the dev-teams.
 
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