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2001 Oldsmobile with a gm 4.3 no spark

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4 years 7 months ago #32836 by EricGoodrich
No spark from coil. Everything I've checked is good. Timing signal to ignitor, control from ignitor to coil, power at coil, no voltage drop in circuit, current ramp is a square rather than a ramp which tells me the coil is shorted but it isn't. A new coil did not fix the vehicle. Any ideas?

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4 years 7 months ago #32837 by Chad
Can you post a screenshot of the coil current and voltage waveforms?

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)

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4 years 7 months ago #32838 by EricGoodrich
Thank you for your reply. Unfortunately I don't. I used my vantage pro instead of my Pico since the car is beached out in the back lot. Consequently I do not have any screenshots.

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4 years 7 months ago #32839 by EricGoodrich
What I can tell you is that the ground side of the coil fluctuated from battery voltage ( cranking voltage ) to zero as the ignitor was commanding the coil. And, the coil current was as about a square wave as I've ever seen on an ignition coil current ramp.

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4 years 7 months ago #32840 by EricGoodrich
I also confirmed no unwanted voltage drop on any circuits for the coil or the ignitor.

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4 years 7 months ago #32841 by Chad
NEW means Never Ever Worked. If you have a good coil, good power supply, and a good ground, then you should see a ramp. If you have a clean turn-off, you should have spark. Voltage and current waveforms would be helpful.

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)
The following user(s) said Thank You: Noah

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