No spark from my coil

Talk and Tech about turbocharged 924/944/968 cars
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Tom
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Mscromer wrote: Sun Mar 22, 2026 12:10 pm Got my repaired DME back from F9. He suggested I get a new coil so I got the MSD coil he suggested. After installing everything it started right up. Ran it for 30 min at 2000 rpm to break in the new cam. Once that was done I set the idle per the factory manuals. Now at idle it is running a little rough. I’m suspecting a vacuum leak somewhere. But can someone that knows what they are looking at look at this data log. The only thing that stands out to me is the KLR knock count is 63 and the fly wheel rpm errors is 17 thanks.
Glad to see you got it running. Congrats. It's literally fine-tuning from here. :angel:

The log says it's running consistently lean, which very well could a vacuum leak, but cold also be other things like the AFM or temp sensors. The main AFM signal looks on the high side if anything, and the DME temp sensor looks like it's at normal operating temp. The IAT temp sensor in the AFM is a little curious though -- remaining at exactly 101F the whole time. It's probably ok and that's just the temp it was seeing, but might be worth testing just to rule it out, especially if you were actually testing in much cooler weather.

With a new build like that, also consider the possibility of a tuning mis-match -- e.g., a chips tuned for a 3 bar regulator or bigger injectors despite actually having a 2.5 FPR or stock injectors, FQS set to wrong setting, etc.

Not necessarily relevant to your issue, but I also notice the ISV is reporting at 85%. I had mentioned to @NCGermerican a few days ago that I thought the ISV 'open' percentage was backwards --i.e., when the F9 software says it's 85% open, it's really 85% closed; and/or the term 'open' is not being used in its most obvious sense to mean how open the ISV valve actually is. If you are in contact with Joe, maybe ask him about that. It very well may be 85% open in your case, especially if you base idle is too low or hasn't been set yet. But if you are lean from a vacuum leak, that 85% might actually be 85% closed, warranting a shout out to joe...

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Mscromer
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Tom wrote: Sun Mar 22, 2026 1:41 pm
Mscromer wrote: Sun Mar 22, 2026 12:10 pm Got my repaired DME back from F9. He suggested I get a new coil so I got the MSD coil he suggested. After installing everything it started right up. Ran it for 30 min at 2000 rpm to break in the new cam. Once that was done I set the idle per the factory manuals. Now at idle it is running a little rough. I’m suspecting a vacuum leak somewhere. But can someone that knows what they are looking at look at this data log. The only thing that stands out to me is the KLR knock count is 63 and the fly wheel rpm errors is 17 thanks.
Glad to see you got it running. Congrats. It's literally fine-tuning from here. :angel:

The log says it's running consistently lean, which very well could a vacuum leak, but cold also be other things like the AFM or temp sensors. The main AFM signal looks on the high side if anything, and the DME temp sensor looks like it's at normal operating temp. The IAT temp sensor in the AFM is a little curious though -- remaining at exactly 101F the whole time. It's probably ok and that's just the temp it was seeing, but might be worth testing just to rule it out, especially if you were actually testing in much cooler weather.

With a new build like that, also consider the possibility of a tuning mis-match -- e.g., a chips tuned for a 3 bar regulator or bigger injectors despite actually having a 2.5 FPR or stock injectors, FQS set to wrong setting, etc.

Not necessarily relevant to your issue, but I also notice the ISV is reporting at 85%. I had mentioned to @NCGermerican a few days ago that I thought the ISV 'open' percentage was backwards --i.e., when the F9 software says it's 85% open, it's really 85% closed; and/or the term 'open' is not being used in its most obvious sense to mean how open the ISV valve actually is. If you are in contact with Joe, maybe ask him about that. It very well may be 85% open in your case, especially if you base idle is too low or hasn't been set yet. But if you are lean from a vacuum leak, that 85% might actually be 85% closed, warranting a shout out to joe...
Thank you so much for your help Tom. I’ll check out that IAT. I’ll also contact F9 and see if the 85% is open or close. So I shouldn’t be worried about the KLR knock count at 63 and fly rpm errors at 17?

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danmartinic
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I understand that AFM IAT sensor is non-replaceable meaning replacement of AFM itself is the only solution for a bad IAT?

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My IAT is 1.1 kohms with an outside air temp at 91. Engine not running.

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Tom
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Mscromer wrote: Sun Mar 22, 2026 4:11 pm My IAT is 1.1 kohms with an outside air temp at 91. Engine not running.
That's a wee bit low for 91F, but I'd guess there's a little heat soak making the sensor see a bit more than the 91 ambient.

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Mscromer wrote: Sun Mar 22, 2026 2:36 pm
Tom wrote: Sun Mar 22, 2026 1:41 pm
Mscromer wrote: Sun Mar 22, 2026 12:10 pm Got my repaired DME back from F9. He suggested I get a new coil so I got the MSD coil he suggested. After installing everything it started right up. Ran it for 30 min at 2000 rpm to break in the new cam. Once that was done I set the idle per the factory manuals. Now at idle it is running a little rough. I’m suspecting a vacuum leak somewhere. But can someone that knows what they are looking at look at this data log. The only thing that stands out to me is the KLR knock count is 63 and the fly wheel rpm errors is 17 thanks.
Glad to see you got it running. Congrats. It's literally fine-tuning from here. :angel:

The log says it's running consistently lean, which very well could a vacuum leak, but cold also be other things like the AFM or temp sensors. The main AFM signal looks on the high side if anything, and the DME temp sensor looks like it's at normal operating temp. The IAT temp sensor in the AFM is a little curious though -- remaining at exactly 101F the whole time. It's probably ok and that's just the temp it was seeing, but might be worth testing just to rule it out, especially if you were actually testing in much cooler weather.

With a new build like that, also consider the possibility of a tuning mis-match -- e.g., a chips tuned for a 3 bar regulator or bigger injectors despite actually having a 2.5 FPR or stock injectors, FQS set to wrong setting, etc.

Not necessarily relevant to your issue, but I also notice the ISV is reporting at 85%. I had mentioned to @NCGermerican a few days ago that I thought the ISV 'open' percentage was backwards --i.e., when the F9 software says it's 85% open, it's really 85% closed; and/or the term 'open' is not being used in its most obvious sense to mean how open the ISV valve actually is. If you are in contact with Joe, maybe ask him about that. It very well may be 85% open in your case, especially if you base idle is too low or hasn't been set yet. But if you are lean from a vacuum leak, that 85% might actually be 85% closed, warranting a shout out to joe...
Thank you so much for your help Tom. I’ll check out that IAT. I’ll also contact F9 and see if the 85% is open or close. So I shouldn’t be worried about the KLR knock count at 63 and fly rpm errors at 17?
Were you logging when you started the motor? If so, start the motor and let it warm up, then capture a minute or so of smooth idling. You can get a lot of knock and flywheel errors while cranking. I doubt either mean much, unless they continually climb as the motor runs.

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Tom
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danmartinic wrote: Tue Mar 03, 2026 4:13 pm
Mscromer wrote: Tue Mar 03, 2026 3:58 pm
Hamburg Technic
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:
Here's the old video I did on your bad FAE sensors. The signal wires should not be connected to the case the way they are in the video... Never heard of this happening to others, so it may have just been a random bad part rather than a systemic problem with FAE sensors at the time... If they shipped a whole batch like this, surely we'd have heard about it and they would have fixed it by now...

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Ah, sweet memories 😁

There was at least one other person with these.. poor guy spent a *year* looking before finding it

Thankfully passed the knowledge on to me relatively quickly

I wonder just how many were sold in that batch and number of people who just gave up

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