OBD2b - OBD1 Conversion & Tach doesn't work

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Nov 23, 2015 | 09:54 PM

#26

Vi_Nation

Honda-Tech Member

Joined: Jul 2014

Posts: 10

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From: Worcester Mass

Re: OBD2b - OBD1 Conversion & Tach doesn't work

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Nov 26, 2015 | 08:19 AM

#27

Honda-Tech Member

Joined: Aug 2008

Posts: 1,197

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From: Ontario, Canada

Re: OBD2b - OBD1 Conversion & Tach doesn't work

You're bumping a 7 year old thread.

Jun 3, 2020 | 04:19 PM

#28

Elijah Major

Trial User

Joined: Jun 2020

Posts: 1

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Re: OBD2b - OBD1 Conversion & Tach doesn't work

Quote:

Originally Posted by C_Rock77

I put a Hondata s300 in my 2001 GSR (installed in an OBD1 P28). Everything started up fine, but the tach did not work. The car was running, but the tach did not work at all. I pulled the Hondata unit out, threw in a stock OBD1 P72 and the same result occurred.

When the S300 was in the car, all the datalogging was working. RPM, Vac, etc. all were working on the display in the laptop. The gauge in my cluster just sat on 0. All other gauges worked: Temp, Fuel, Speedo. The tach just sat on 0. Pulled everything out, and put the stock OBD2b ECU back in, and everything worked fine.

The GS-R is SC'd and running the JRSC hack and FMU. It started throwing the code for the Atmospheric sensor. I picked up a Hondata S300 and was going to put the unit in and run a stock P72 map in it (still running the JRSC hack) until I can get the cash to take it to the tuner. Now, seems like I have other issues.

Any suggestions?!

So on your distributor there’s a blue wire with light blue “highlights” or stripes or whatever you want to call them. This is the one that send signal to the tach. Take it and a length of wire, and look at your engine bay on the drivers side near the firewall where your harness is emerging. There’s a wire with a plug in connected to a wire on the harness. It’s the only one with a connector and butt on it if you have a factory harness. Connect the two. Your tach will work fine. Add some shrink wrap or electrical tape and add it to your harness and your tach works. I had the same issue. Good luck!