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#1 |
Registered User
Join Date: Jan 2009
Location: enumclaw wa
Posts: 58
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tach question
I'm told there is a link you can get to put in the wire from the coil to the tach to make our tachs work with hei, anyone know anything about this?
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#2 |
Registered User
Join Date: Sep 2003
Location: New Salem, ND
Posts: 1,558
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Re: tach question
I just ran the brown wire to the "tach" terminal on my HEI distributor. I am using a harness that I bought though so I am not sure if your wire color would be the same.
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07 Chevy classic LBZ Duramax (a few mods) '67 Chevy 1/2 ton 2wd (in pieces) '69 Chevy 1/2 ton 2wd (on hold) '71 GMC 3/4 ton 4x4 ‘71 GMC 1/2 ton 2wd suburban |
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#3 |
Moderator
![]() Join Date: May 2007
Location: Southern Cal
Posts: 20,004
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Re: tach question
x 2
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1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man |
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#4 | |
Account Suspended
Join Date: Jan 2007
Location: Tucson
Posts: 2,183
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Re: tach question
Quote:
http://www.repairconnector.com/produ...Connector.html |
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#5 |
Registered User
Join Date: Jan 2009
Location: enumclaw wa
Posts: 58
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Re: tach question
I think I need to clarify the tach is hooked up and works but it's inaccurate and wont go past about 3200 rpm I'm told that is because it's hooked to hei and there is some kind of resistor or something you can put in the wire to the coil that will make the tach happy with hei.
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#6 |
Registered User
Join Date: Sep 2003
Location: New Salem, ND
Posts: 1,558
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Re: tach question
There isn't a resistor in my harness? Can you find out if it is accurate up to 3200 rpm? Maybe it isn't calibrated right. Do you have a v6 or v8 engine?
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07 Chevy classic LBZ Duramax (a few mods) '67 Chevy 1/2 ton 2wd (in pieces) '69 Chevy 1/2 ton 2wd (on hold) '71 GMC 3/4 ton 4x4 ‘71 GMC 1/2 ton 2wd suburban |
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#7 |
Senior Member
Join Date: Nov 2003
Location: Brookings, SD
Posts: 10,497
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Re: tach question
A stock tach will work just fine with standard HEI without any modifications.
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Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs. |
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#8 |
resident oilfield trash
Join Date: Jan 2009
Location: Lubbock TX
Posts: 1,465
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Re: tach question
I know I ordered my tach harness from GMC Pauls and it is specific for a hei set up. So that may be what you need to do
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1967 SWB C10 396/400 factory air factory tach (sadly had to send to a new home) 1986 Honda 70 Fourtrax 1991 Chevrolet K5 blazer 2wd 1982 Mastercraft Pro Star 190 Stars and Stripes 2002 Chevrolet Tahoe 2011 Nissan Armada ![]() |
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#9 |
Registered User
Join Date: Oct 2007
Location: Valley Springs, Ca
Posts: 857
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Re: tach question
if you have switched over to HEI you will also need to get rid of the ballast resistor due to you are not using points any more, a ballast resistor can cause all sorts of issues even with the Tach.
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#10 | |
Registered User
Join Date: May 2004
Location: Topeka, Ks
Posts: 2,293
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Re: tach question
Quote:
Mine is also a bit inaccurate, it actually reads higher than it should as RPM's increase. I have done a little research and have found that the HEI tach signal is a digital signal and the old tachometers are analog device's that expect to receive an analog signal. They just don't work very well together but can be improved if you add a tach filter. If you do a google search you will find many examples and I have added a link to an ebay item that may help in your situation. I have wanted to try one of those myself, just haven't gotten around to it. Monte Carlo Tach filter Here is a link to good info over on the vette forum Tach filter
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I'm not a pessimist, I'm just optimistic that bad things are going to happen. 1971 Cheyenne Super K10 - tilt, cruise, air, am/fm, tow hooks, factory buckets! 1986 Jeep J10 pickup, - 5.3L Vortec with 4L60e and NP241. |
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#11 |
Registered User
Join Date: Jan 2009
Location: colorado springs
Posts: 479
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Re: tach question
double check the directions to see if there is a calibration that needs to be done, mine for example can be used on anything from a 2cyl to 12cyl, so when I hooked it up I had to go through the calibration proccess to get it acurate. List the brand and part # and I bet someone can help, good luck
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