Poor earth

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brett nz
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Joined: Sat Jun 08, 2013 10:50 pm

Poor earth

Post by brett nz » Fri Jan 31, 2014 3:21 am

Hi all, have been having a play with a 96 Subaru Grandwagon BG9 EJ20 for training more than anything else. Had some issues but they are sorted.

Had a look with scope at primary ignition and earth is only reaching 700mv when switch closes and is up to 4V by the time switch opens. I have checked and cleaned earths where listed in wiring diagram at top of engine and on top of strut tower with no change.

This has 2 DIS coils, 3 wires, 2 that go to the ignitor and then onto earth. Thing that confuses me is when measuring on either of the 2 that go from coil to ignitor, looking at primary ignition i see this big earth loss but if i measure on the other side of ignitor on the earth wire i only get 5mv loss. Now this origionally made me thing dodgy igniter but i had one here and tried it with no improvement. Is this rise in earth voltage current control? I does not flatten out at all like i have normally seen.

Thanks for any input.
Subaru poor earth.JPG

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Re: Poor earth

Post by Robski » Fri Jan 31, 2014 7:28 am

where's the current on another channel ?

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Re: Poor earth

Post by yori131 » Sun Feb 02, 2014 5:42 am

dont know much my self but have you try to see what the current is doing i think that differnece seems like a current limter

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