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ignition module testing

Immortality

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does anybody know how to test the ignition module. i had a fualty coil which i replaced but i've still got no spark on the 2 cylinders from that coil, the other cylinders seem fine and have spark (tested with old spark plug earthed out). pulled the coil off and put my meter accross the 2 pins that go into the coil. i've got 14.4volts there but i'm sure it needs to be switching from high to low to have the coil fire and it doesn't seem to be switching?
 

vt1538

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Normally you would put a test light between the 2 terminals and crank the engine. The test light should blink while you are cranking the engine. The terminals under the coil that is.
 

kopper69

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Im not aware of any tests that will prove the operation of a dfi module. Make sure the cable on the side is nice and tight, and maybe take it off and give it a clean.
 

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Normally you would put a test light between the 2 terminals and crank the engine. The test light should blink while you are cranking the engine. The terminals under the coil that is.

yeah, that is what i thought also, just i did it with the engine running with only 2 coils connected but then it didn't go 14v - 0v - 14v - 0v(using a multi meter to test range/high/low voltage) etc it just stayed high at 14v so i'm pretty sure the module must be faulty unless there is a reason that the ecu wouldn't be switching one coil witch seems highly unlikely:bang:
 
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jc58nc

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I'd try that test again but with a test lamp, the ignition module would have a capacitor across it's output for spark quenching and would hold the voltage up like a battery and not show on your meter. The test lamp would draw more current and discharge the capacitor and should show the pulses when cranked.
 

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so i got the new dfi module, fitted it all up, turned the key......nothing. it cranks but doesn't fire at all. now thats got me doubting my own diagnostic skills. so i put the original back in the car and it runs on 4 cylinders. tried it all again and still nothing. so i put the original faulty module in the VN and it fires on four cylinders. then did the same with the new module and it doesn't work in the VN also.:bang: put the VN back to original and it works fine. so the new module is faulty in my book also. took it back and it was the only one they had in stock in the whole country. checked with Holden and they want $456+gst for it. that seems like a rip to me. considering a second had one for $100 from the local wreckers now:bang: :bang: :bang:
 

vt1538

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I think it was repco that had them on sale for $135. I would give them a try.
 

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appco is a division of repco here in NZ, the faulty new unit was $252 and that was about a trade price at that. stuff is very expensive over here, it sucks
 

vt1538

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I noticed your location just after I posted. Sorry about that. When I recently bought a dfi with coilpacks from the wreckers here it cost me $145 with a gaurantee to work or they would replace it.
Hope it all works out for you.
 
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