BUILD THREAD Project Olds Cool (Recognition!!)

pontiacgp

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Mar 31, 2006
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Kitchener, Ontario
What about playing it by ear, unplug your tach and rev the car at what you think is 3000, then ground the grey wire to see if the engine stalls. I think it's something involving your tach that causing the issue. If that works you can always reset it when you have another tach to use
 
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Rktpwrd

Builder of Cool Shjt
Supporting Member
Feb 2, 2015
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Calgary, Alberta, Canada
What about playing it by ear, unplug your tach and rev the car at what you think is 3000, then ground the grey wire to see if the engine stalls. I think it's something involving your tach that causing the issue. If that works you can always reset it when you have another tach to use

lf I’m not mistaken, the module needs to “see” the tach to set the limiter. I tried grounding the grey wire when it wasn’t tied into the tach wire which is essentially the same thing you’re suggesting, but it did nothing.

I do agree tho, I believe it has something to do with the tach circuit, maybe not necessarily the tach itself. I’m starting to suspect it might have to do with the tach filter, but I’m currently unable to locate it in the harness.
 
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Rktpwrd

Builder of Cool Shjt
Supporting Member
Feb 2, 2015
4,180
23,991
113
Calgary, Alberta, Canada
The tach filter is on the firewall

Negative.
My tach wire goes directly from the distributor cap through the firewall, no filter mounted to the firewall. I even removed the grommet and pulled some slack tach wire through and still no filter. And it’s all original to the car, not added on or tampered with.

I just had a thought, what if it’s the coil that’s causing the issue? Somehow grounding out the coil causing it to shut the car down maybe?
 
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pontiacgp

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Mar 31, 2006
29,270
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Kitchener, Ontario
I thought all the G bodies had the filter on the firewall, anyway I just looked at the instructions again and have you tried plugging the tach in the normal regular connection on the cap?
 
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TURNA

Rocket Powered Basset Hound
Jul 24, 2009
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Socialist NY
It has 47 reviews just on Summits site and 15 of them are poor (3stars and down)


To me that not good for the so called "leader" in automotive electronics.

The Davis module has 28 reviews all 5 star.
 
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pontiacgp

blank
Mar 31, 2006
29,270
20,413
113
Kitchener, Ontario
It has 47 reviews just on Summits site and 15 of them are poor (3stars and down)


To me that not good for the so called "leader" in automotive electronics.

The Davis module has 28 reviews all 5 star.

I'm hoping that Donovan will be the 48th review giving it 5 stars
 
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pagrunt

Geezer
Sep 14, 2014
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Elderton, Pa
I thought all the G bodies had the filter on the firewall, anyway I just looked at the instructions again and have you tried plugging the tach in the normal regular connection on the cap?
They all are mounted on the firewall (I'll exclude '86-'87 GN & the GNX since I know nothing on their set up.) Buy chance an earlier owner cut it off thinking there was an issue?
 
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Texas82GP

Just-a-worm
Apr 3, 2015
7,989
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Spring, Texas
Donovan,

12" of vacuum seems pretty low. What are the cam specs? Did you post them already? If so, I apologize for the question. How do the power brakes feel? For grins, you might disconnect and plug the hose to the booster and see if you get a better reading on the vacuum gauge.
 
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Oct 14, 2008
8,831
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Melville,Saskatchewan
Sucks to hear about the new MSD HEI module. I really like the Ignitor 3 module, a rev limiter and almost multi spark. I have blown 2 of them, one was my fault. The other, I had an issue with the power wire, not putting out enough voltage and it died. I have it in my 88 Cutlass, right now. I would check how far the secondary air door is opening, betting it is serverly limited. Cliff's book shows how to measure and it has different recipes for different motors. Also probably your extremely lean secondary rods are limiting it. I can feel my secondaries open and feel the rush on my 70S.
 
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