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Pertronix ignition module testing...


73Riviera's Avatar
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07-17-04, 05:18 PM   #1  
73Riviera
Pertronix ignition module testing...

Is it possible to test a pertronix ignition module? Is there an easy/moderately difficult way to test it myself, or is there a branch of automotive parts stores that will do it for free? I'm pretty sure the module has gone out, but I want to be sure before I replace a non returnable electrical part. Any help you can offer is greatly appreciated.

 
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07-17-04, 05:55 PM   #2  
There is equipment available to test modules but it isn't very common. Check to see if you are getting pulse to the negative side of the coil. That would narrow it down to module or dist pick up/crank sensor.

 
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07-19-04, 09:31 PM   #3  
73Riviera
I had no luck with a pulse at the negative end of the coil. Maybe I can feed you some specific information on the car and the problem and you can let me know if Iím at least barking up the right tree.
The car is a 1973 Buick Riviera with a 455 ci 8 cyl engine, air conditioning, power steering and brakes, and a turbo 400 automatic transmission. The distributor itself is a stock replacement with the points switched out for a Pertronix ignition module. The distributor retains its vacuum advance and also its advance weights and springs, but the points and condenser are replaced with the Pertronix ignition module and its pickup ring, which is a plastic ring mounted to the rotor with magnets that trigger its firing. I've had this ignition setup for almost two years and it has always worked fine.
The problem I am trying to resolve by testing the ignition module is a stuttering of the engine when it is initially put under load. If I step on the gas with any kind of authority (either from a dead stop or if I am already moving) the engine stumbles and stutters for 4 -5 seconds, but eventually catches up with itself and runs cleanly.
I've checked the timing with and without the vacuum advance connected from the distributor to the carburetor, and it makes no difference. I've also verified that the fuel pressure is fine going into the carburetor.
The engine temperature has no affect on the behavior.
Thank you again for helping me with this, and please let me know if there is any more information that I can provide that would help you to understand the problem.

 
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07-20-04, 03:19 AM   #4  
It is possible you could be on the right track but it's going to take a scope to prove it.
I would also check to make sure the accelerator pump is working in the carb. Does feathering the throttle seem to make any difference? Check for side to side play in the distributor shaft. Check for corrosion on the coil tower. You could ohm out the pick up coil if you have any specs available. I would probably consider the module the least likey to cause a problemlike that but anything's possible.

 
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07-20-04, 07:31 AM   #5  
I don't know if this would be your problem, but I believe this unit needs to be connected directly to a hot, switched 12v source. Some cars use a resistor wire for the original setup. This resistor wire needs to be replaced by a switched 12v lead. Check your instructions and check the wiring diagram for your car. Search the net to see if you can find a group of similar people to help you out with this issue. Here's a start...

http://www.aaca.org/ubbthreads/ubbthreads.php?Cat=

 
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07-21-04, 02:11 PM   #6  
73Riviera
found the gremlin

It did turn out to be a bad ignition module. It turns out that the Pertronix equipment can only handle stock ignition coils, and I have a pretty nasty Accell coil that I put on a few weeks back. I'm replacing the ignition module tomorrow and also adding in a Pertronix coil that is guaranteed to be compatible. I've gone back through some documentation and didn't find anything out about compatibility, and there also isn't really anything on the website either. I found out from and auto parts counter person who had run into the same thing and contacted Pertronix directly.
Thanks for all the help, and I'll just chalk this one up to learning experience.

 
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07-21-04, 03:43 PM   #7  
Interesting................

That's some good info.

 
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07-22-04, 05:58 AM   #8  
I do remember reading Petronix technical information that stated anything more powerful than the stock coil may damage the ignition module. It's there somewhere.

Essentially, if you want to upgrade from points one has to choose between the Petronix setup or go with the high-energy MSD/Accel setup.

 
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