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04-08-2020, 10:45 PM | #1 |
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Fast xfi rpm issue
Fast xfi, analog 7al2, fast dual sync dist. My autometer tach is roughly 500rpm less than what fast data shows. Fast at idle shows 1100 while tach is around 600. Is this normal or if not, what is the fix. I honestly thought I had a low reading tach before I put on efi, just now I have another reference that should be super accurate since its dual sync
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04-09-2020, 08:34 AM | #3 |
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Re: Fast xfi rpm issue
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04-09-2020, 09:25 AM | #4 |
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Re: Fast xfi rpm issue
Where are you picking up the tach signal?
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04-09-2020, 09:57 AM | #5 |
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Re: Fast xfi rpm issue
at the 7al2 box, tach terminal
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04-09-2020, 10:34 AM | #6 |
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Re: Fast xfi rpm issue
Is there an unused tach wire on the FAST harness? If there is, it would be worth trying before changing the tachometer.
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04-09-2020, 11:31 AM | #8 |
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Re: Fast xfi rpm issue
I have not had a tach in my car for a while now. I log & play back every pass. If I had a stick car, I would need one, wouldn’t I? Or a shift light. LOL
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04-09-2020, 02:57 PM | #9 |
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Re: Fast xfi rpm issue
That's what is firing the msd box. Seems the more people I talk to I am thinking it's a tach issue. Nobody seems to have this problem. And a Tach is a necessity in Stock. Foot brake, and reverse pattern ATI 350 means it's all on me lol
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04-09-2020, 08:57 PM | #10 |
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Re: Fast xfi rpm issue
I have used a digital hand held tach that uses a small piece of reflective tape on the damper to verify which is correct.
Ernie Neal SS 354 |
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