Hi, thanks for looking

I have a 69 Deville convertible with a 472.

I have made the pertronix conversion a while ago, and wanting to get more spark from my ignition system, I tried replacing the braided resistance wire that goes to the coil with a regular wire from the starter (as is mentioned in other posts here)
The problem is the car runs like crap once I do this...

Any ideas welcome

All the best

You asked -

Put your old points and condenser system back in - are you drag racing or something to need that pertronix - or whatever its called? :confused:

Thanks for your reply Mike.

The car runs really well with the pertronix unit installed.
Having searched on these forums, many have said that once installed, you should remove the resistance wire to send full 12V to the coil, which the previous points and condenser couldn't handle. In theory getting a stronger spark.

No, I'm not going drag racing, I live in Ireland and not having to change points and condenser, I can save money on parts and shipping from the US !

Cheers

Jon

I don't think you can just remove the resistance wire. I have a similar system installed on my 500 CID Eldorado. I agree, once set up it rides a lot better and possibly more importantly it runs more efficiently. Mine is one that just drops into the old point style distributer so I'm not sure how similar our systems are, but I needed to install a ballast resistor to even out the flow to the distributer in order to keep it running smoothly. If you have a a loom type resistance wire equipped than you don't need the ballast resistor, but assuming you don't have one you'll need a ballast resistor to get the car to run correctly.

Bah, Humbug :stirpot:

Points suck. A good electronic system setup properly will prove this every time. Maybe the system you used is designed to run with the resistance wire still in the circuit. Lots of retrofit systems were. The posts on this board generally refer to bypassing the resistance wire using the GM H.E.I. system retrofitted into a points equipped car. Your system could be different. Too much available spark voltage will make the car run poorly. The resistance wire isn't a big deal with an H.E.I. conversion either. GM H.E.I. still makes plenty of unloaded secondary available voltage with the evil resistance wire in place.

Thanks Ape Man

Good words.

On the instructions for the pertronix unit, it said if you have a ballast resistor in place, then don't remove it. It's really unclear what to do if you have a braided resistance wire.
I'm aiming for the best spark from my ignition. I've had this thing running really well with various combinations of plug gap and timing. Best was .060 gap. but after reading that high compression engines need small gaps and a strong spark, I reduced it to .40, still sounds nice but not as smooth and growly .... I may increase it again. My timing light turned out to be a piece of crap and no longer works (2 weeks!!) So I have been making small adjustments and test drives... never been able to get it to run really smooth at all rpms ?? Should a 69 472 in decent tune sound really nice at all rpms and loads ?

cheers

Jon

A resistor and resistance wire perform the exact same task so leave it there. You might have additional instructions for a recommended voltage drop across the resistance wire. Takes a little kung-fu to read this in your situation.
Many Cadillac engines of this design do not idle very well. The uphill intake works much better with just air and gasoline introduced via port fuel injection. The rest of the RPM range should be quite smooth.

HI Jon
my cadillac has the HEI ignition but i have just put the pertronix in my 74 450sl. any v8 needs either a coil with an internal 1.5 ohm ballast or an external 1.5 ohm ballast. anything else and it works like crud.
I ended up buying the 40 000 volt flamethrower coil off ebay for $26 and it works great. just make sure you have the full 12v+ ignition switched power to the + pole of your coil or ballast(depending on internal or external) because if you are even a tiny bit below 12v nominal then it also works like crud
hope thats some help
cheers
Barri