Tachometer and ECU disagree

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Dec 20, 2011 | 06:45 AM

GagnarTheUnruly

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From: Mountains

Tachometer and ECU disagree

My tachometer reads a bit lower than my ECU (at 8500 indicated I'm at 8000-8200 on the ECU, as far as I can tell). Which should I trust?

I'm logging with Neptune

Dec 20, 2011 | 07:21 AM

HRTuning

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From: Phoenix, AZ, USA

Re: Tachometer and ECU disagree

The ECU. If the ECU was "off" from what your engine was actually doing, your car wouldn't be running very smoothly. The stock tach can be off by several hundred RPMs at certain points.

Dec 20, 2011 | 11:59 AM

josephcmiller2

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Re: Tachometer and ECU disagree

I had a tach once that was off by 1,000 RPMs. I didn't use it very long.

Dec 20, 2011 | 12:48 PM

RC000E

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From: I'm everywhere Focker

Re: Tachometer and ECU disagree

Always trust the ecu when compared to an analog gauge. I dont think I have ever seen a dead accurate boost gauge or tach...lol.

Dec 20, 2011 | 12:50 PM

Aradin

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From: Maryland.

Re: Tachometer and ECU disagree

The ECU is correct. My tach is off up to 800rpm some days, others it reads fine.

Dec 20, 2011 | 04:15 PM

0mtber

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From: Tampa, FL

Re: Tachometer and ECU disagree

I have seen plenty of tachometers that are off 500-1500 rpms... Trust the ecu.

Dec 20, 2011 | 06:27 PM

GagnarTheUnruly

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From: Mountains

Re: Tachometer and ECU disagree

Will do, thanks

It's little disconcerting watching the needle swing so far past redline but at least the TunerView is accurate!

Tachometer and ECU disagree

Tachometer and ECU disagree

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