I have a 69 with a 406 and I wanted to upgrade my ignition from the protronix kit in the old points style distributor .I installed Summits ready to run setup. Everything went together fine ran fine after setting timing to specs,but my tach reads @ 1000 at idle then when you accelerate it pegs to 0. I have called Summit and no one has ever heard of this(they insist on sending me a replacement). I have triple checked all wiring,granted this isn't rocket science and still no change. Just wondering if anyone has run into this in the past.

Danny

 

Factory in-dash tach, or aftermarket?
Full 12 volts supply to the coil?
Pertronix coil or other?
The Pertronix coils (I, II, III) have different & specific ohm readings that want to be matched to their respective ignition system. They tell you to not use a stock type of coil. Don't know if a mismatch issue happens when using a Pertronix coil with a non Pertronix ignition. But if you still are still using a Pertronix coil, I'd swap it out for a different type of coil.

 

I have the factory RS package with factory tach and the distributor is the Summit Ready to run.
I installed their recommended coil as well. All should be a plug and play,but we all know how that can go sometimes. I am gonna try the new replacement Distributor when it comes,just maybe that or a bad ground will fix it.

Thanks

 

Ok, that's why I was wondering if you had a factory tach or not. Might as well try the replacement distributor since it's coming to rule it out, but....
My factory tach will not work with my HEI or electronic distributor. | American Autowire

 

I believe youre right. I will try the new install,so I might see if I can find a tach filter locally.I appreciate you're input.I will keep you posted.I had seen a you tube video of someone making one from diodes as well..

 

Well got the new replacement distributor and back to square one. I guess I will order the filter then try the interface people have mentioned. i read somewhere I could send my Tach to someone who could upgrade it.Any thoughts on that? I guess i should have spent the $500 bucks plus and went another route after all.....

 

As 69 suggests, OE tachs only work with OE ignition systems.
Different waveforms generated by different ign systems, OE point set vs. electronic.
Yes, you may need a tach filter, MSD sells one, whether it would work or not IDK.


You might borrow an aftermarket tach and check operation.

 

we had an old snap on tool that showed proper rpm and it worked as one should.

 

HEI equipped GM vehicles (early 70's-on) with a factory tachometer used a tach filter for this reason. Just pick one up that's for a stock GM, either new or used one from a boneyard.

 

Update....I picked up an Autometer filter kit and that did the trick.Thanks for all you guys input and help!

Danny