LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Losing tach signal.

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Old Jun 16, 2008 | 11:52 AM
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MEAN LT1's Avatar
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Default Losing tach signal.

It seems the higher the motor spins up my tach gets jumpy. It usally happends in the higher rpms bands like 5700 and up. I went tot he track recently and when Ithought I was shifting at 6500 I was only shifting at 5800-6100. Anyone else experience this?. I guess the only way to prevent this is to get a shift light or aftermarket tach.
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Old Jun 16, 2008 | 02:08 PM
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Everyone says the tach is around 200rpms off, yet time and time again, mine is reading the exact same as the ECM :\ Mine's a fluke I guess.

So anyways, it's probably that your gauge just is off like the rest. Run your own wire and tach from the coil if you don't like it lol It's only 1 wire.
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Old Jun 16, 2008 | 03:28 PM
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Originally Posted by Formula350
Everyone says the tach is around 200rpms off, yet time and time again, mine is reading the exact same as the ECM :\ Mine's a fluke I guess.

So anyways, it's probably that your gauge just is off like the rest. Run your own wire and tach from the coil if you don't like it lol It's only 1 wire.
What sucks is that I logged all my runs from the track on saterday. When the tached showed around 6500 rpms. Per Datamaster it was only 6000 or in most cases 5800.
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Old Jun 16, 2008 | 06:31 PM
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Mine has a conditional missfire, with tach jump. Still in the process of diagnosing. Only difference, Mine will jump all over, from idle, to wot.
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Old Jun 16, 2008 | 07:45 PM
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Originally Posted by MEAN LT1
What sucks is that I logged all my runs from the track on saterday. When the tached showed around 6500 rpms. Per Datamaster it was only 6000 or in most cases 5800.
hah I really don't know what to tell you then :\
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