No spark from my coil

Talk and Tech about turbocharged 924/944/968 cars
Mscromer
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I have sent Focus 9 a data log. Waiting to hear back from them on what they see.

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danmartinic
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Mscromer wrote: Tue Mar 03, 2026 3:58 pm
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Tom... please provide the simple test to determine the sleeve-grounding problem on the sensors (or whatever it was I forget) using a multimeter :thumbup:

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Tom
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Mscromer wrote: Tue Mar 03, 2026 4:00 pm I have sent Focus 9 a data log. Waiting to hear back from them on what they see.
Post the logs here, we can look at them too. :)

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Mscromer
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Tom wrote: Tue Mar 03, 2026 7:05 pm
Mscromer wrote: Tue Mar 03, 2026 4:00 pm I have sent Focus 9 a data log. Waiting to hear back from them on what they see.
Post the logs here, we can look at them too. :)
Here’s the data log. Scroll down until u can see where I started trying to start the car. I’m really thinking it’s my sensors that are bad.
Porsche Log-134170476263195312.csv
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johnb
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Mscromer wrote: Wed Mar 04, 2026 5:43 am
Tom wrote: Tue Mar 03, 2026 7:05 pm
Mscromer wrote: Tue Mar 03, 2026 4:00 pm I have sent Focus 9 a data log. Waiting to hear back from them on what they see.
Post the logs here, we can look at them too. :)
Here’s the data log. Scroll down until u can see where I started trying to start the car. I’m really thinking it’s my sensors that are bad.
Porsche Log-134170476263195312.csv
What is it in the log that makes you think that? There's a plausible looking spark advance value once your cranking rpm gets to around 200.

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Mscromer
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johnb wrote: Wed Mar 04, 2026 6:03 am
Mscromer wrote: Wed Mar 04, 2026 5:43 am
Tom wrote: Tue Mar 03, 2026 7:05 pm

Post the logs here, we can look at them too. :)
Here’s the data log. Scroll down until u can see where I started trying to start the car. I’m really thinking it’s my sensors that are bad.
Porsche Log-134170476263195312.csv
What is it in the log that makes you think that? There's a plausible looking spark advance value once your cranking rpm gets to around 200.
It’s nothing in the log that makes me think it’s the sensors. I don’t really know what all the values should be in the log. Just in all my research on this no start issue always usually points to the sensors. I’m waiting for anyone here and focus 9 to look at the data and say if it is definitively the sensors or something else.

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johnb
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Mscromer wrote: Wed Mar 04, 2026 7:02 am
johnb wrote: Wed Mar 04, 2026 6:03 am
Mscromer wrote: Wed Mar 04, 2026 5:43 am

Here’s the data log. Scroll down until u can see where I started trying to start the car. I’m really thinking it’s my sensors that are bad.
Porsche Log-134170476263195312.csv
What is it in the log that makes you think that? There's a plausible looking spark advance value once your cranking rpm gets to around 200.
It’s nothing in the log that makes me think it’s the sensors. I don’t really know what all the values should be in the log. Just in all my research on this no start issue always usually points to the sensors. I’m waiting for anyone here and focus 9 to look at the data and say if it is definitively the sensors or something else.
Fair enough. The reason that bad sensors cause a no-start condition is because the DME needs them to generate the spark and injector signals. When you see the tachometer bouncing consistently during cranking, that indicates that the DME is generating the ignition signal, so you should be getting a spark. The log seems to confirm that the DME is generating a spark signal.

For reference, here's what it should look like:


It is definitely possible to have a spark and still no start because the spark timing is wrong, which could in theory be caused by a crank sensor/harness problem. But you would still be seeing the spark with a spark tester in that case.

When you have consistent tach bounce but a spark tester indicates no spark, and a new wiring harness, I'm guessing that points to something not being wired up correctly, or a bad KLR.

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Mscromer
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johnb wrote: Wed Mar 04, 2026 7:18 am
Mscromer wrote: Wed Mar 04, 2026 7:02 am
johnb wrote: Wed Mar 04, 2026 6:03 am

What is it in the log that makes you think that? There's a plausible looking spark advance value once your cranking rpm gets to around 200.
It’s nothing in the log that makes me think it’s the sensors. I don’t really know what all the values should be in the log. Just in all my research on this no start issue always usually points to the sensors. I’m waiting for anyone here and focus 9 to look at the data and say if it is definitively the sensors or something else.
Fair enough. The reason that bad sensors cause a no-start condition is because the DME needs them to generate the spark and injector signals. When you see the tachometer bouncing consistently during cranking, that indicates that the DME is generating the ignition signal, so you should be getting a spark. The log seems to confirm that the DME is generating a spark signal.

For reference, here's what it should look like:


It is definitely possible to have a spark and still no start because the spark timing is wrong, which could in theory be caused by a crank sensor/harness problem. But you would still be seeing the spark with a spark tester in that case.

When you have consistent tach bounce but a spark tester indicates no spark, and a new wiring harness, I'm guessing that points to something not being wired up correctly, or a bad KLR.
Well I have rang out the wires for the sensors to make sure they were not pinned wrong and everything is correct. Also ohmed out the wires to make sure there wasn’t a slight break somewhere. . I also by passed the KLR and still no start.

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danmartinic
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Long time since I had the aftermarket sensor issue.. but I found the old thread

Just don't recall (and didn't seem to mention) if I had tach bounce or not?

Anyway, if you take a multi-meter set on continuity and touch the sleeve of a sensor with one prong and any plug pin with the other, you should not have continuity (beep) with any pins

With my FAE sensors, I indeed had continuity with at least one pin. They tested fine when installed... but the DME would shut down upon sensing this manufacturing defect.

It took someone with a year of troubleshooting to come into the chat and tell me this possibility which helped me solve the no-start in about a month instead.

Anyway, just putting it out there *just in case*

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PSU_Crash
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I'm not familiar with the F9 ECU, but on others I have setup there is a cranking RPM Threshold. Below that, no spark. Although I do see the timing advance coming in, so probably not likely.

Does the F9 take the place of the factory ignition module? I have had a dead ignitor on other projects in the past that acted just like you are saying.
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