TBI->carb...tach probs

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Dec 30, 2002 | 06:40 PM
  #1  
have a built 357 in a 92 rs...threw out the 305 ...

now.. i know that the TBI motor has a 2 connector coil...and i found the red battery wire and the white tach wire...but when i plug in the tach wire it my tach doesnt work...i have a HEI accel supercoil...and i can get the damn thing to work...thats the only flaw thats holding my car back in a way...i also have a MSD 6 AL ign system...what do i have to do to make my tach work???....

im thinking bout saying screw it and buy a 5 inch tach...

also..the red battey wire is the switch for the box to turn on...what should i do with the white wire...i tried the tach connector...dont work...

HELP
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Dec 31, 2002 | 09:10 PM
  #2  
It won't work if connected to the coil wire (where the tach used to get it's signal from in stock wiring configuartion) once you install the MSD box. There's a terminal on the side of the MSD box specifically for driving the tach signal wire. Using this terminal has always worked for me.

If you don't have a set of instructions for how to hook up the MSD I believe you can download it off of the MSD website. There's a special way it has to be wired to work with the computer-controlled divorced coil HEI ignition.

On my non-computer controlled HEI distributor the white wire does not get used. I leave it neatly coiled up near the box.
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Jan 1, 2003 | 12:35 AM
  #3  
yea u gotta run it through the msd box or u can use the factory one i believe but i think u have to have some kind of filter for it. thats what i was told i was in ur shoes not to long ago. mine was off by like 1000 rpms. except at idle it was right.
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