tach is way off

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Oct 18, 2014 | 06:20 PM

ws6turbo

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tach is way off

So I got a 97 ws6 and recently swapd my 13:1 lt4 with 24x swap for a ls2 with a dbw Ecu.. e40 I believe and now my tach is off by aprox 50% . Now I've read about the pull up resister install. Will this fix my problem or will I need a Dakota digital calibrator? Someone has to of done this before I'm sure.. any help would be cool

Oct 18, 2014 | 07:17 PM

ws6turbo

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Anybody?

Oct 19, 2014 | 10:09 AM

i r teh noobz

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The LS PCM outputs a 4cylinder tach signal if I remember. The signal can be changed in HPTuners.

Oct 19, 2014 | 02:59 PM

1970camaroRS

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Quote:

Originally Posted by i r teh noobz

The LS PCM outputs a 4cylinder tach signal if I remember. The signal can be changed in HPTuners.

Yep, need to change the output signal with a tuner.

Oct 20, 2014 | 08:05 AM

TipsyMcStagger

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Quote:

Originally Posted by i r teh noobz

The LS PCM outputs a 4cylinder tach signal if I remember. The signal can be changed in HPTuners.

I have an LS2/E40 that I'm swapping into an E36 BMW. Based on my research, the tach signal cannot be adjusted in the E40 PCM. I'm not stating this as fact but I know of at least two other LS2/BMW swaps that required the Dakota Digital box, one of which was previously an LS1 that had the necessary tach adjustment made in the 411 (LS1) PCM.

If the OP determines the signal can be adjusted in the E40 PCM, please post here and let us know.

Tipsy

Oct 21, 2014 | 09:45 PM

superdave84

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Quote:

Originally Posted by TipsyMcStagger

I too have the LS2 and E40. I have tried to program the tach (Speedhut), and it refuses to do as I command. Right now it sits at 5k whether it's at WOT or idling. I got tired of messing with it. If anyone has a solution, please let us know.