# 67 400 w/No Spark?



## jodyB (Oct 2, 2016)

So, I parked my GTO in the garage a week ago and came out this morning and it wont start. When the key is turned the starter turns the motor over fast and hard. Carb is getting fuel. Checked for spark, no spark at the Plugs. 

The engine is a 67 400, with no points, but a Printronix's HEI set up. Rotor is turning fine, the wires are hooked up correctly from the distributor to the coil. I have12 v from a new battery to the ignition switch. 

However, only 4.9 volts at the + post on the coil with the ignition in the run position. When the motor is cranked, The volt meter only reads 9.7 volts at the + post. Then with the coil wire disconnected and my voltmeter stuck in the coil wire it reads as high as 15 volts and jumps as low as 8 volts as the starter turns the engine. Lastly, with a spark plug put in the end of the coil wire there is no spark when the engine is cranked. The coil is new. I am stumped on this one guys. 

Now, I am wondering if the ignition switch might be bad? any ideas?

Joe


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## PontiacJim (Dec 29, 2012)

jodyB said:


> So, I parked my GTO in the garage a week ago and came out this morning and it wont start. When the key is turned the starter turns the motor over fast and hard. Carb is getting fuel. Checked for spark, no spark at the Plugs.
> 
> The engine is a 67 400, with no points, but a Printronix's HEI set up. Rotor is turning fine, the wires are hooked up correctly from the distributor to the coil. I have12 v from a new battery to the ignition switch.
> 
> ...


With the electronic conversion, you HAVE to have 12V to the coil. The original points types distributor uses a resistance wire to lower the 12V down to something like 8V so it does not burn out the points. It sounds like this is what you are experiencing with the numbers you have. There are a number of topics on the forum which have covered this if you do a search.

Running the electronic distributor on lower voltage can also damage the internals and you may have also experienced this. I would first try to get the needed 12V to the coil and if you do, and still does not fire up, it may be the electronic module has gone bad inside the HEI and I assume like the original HEI's, you can replace it.

First up, I would run a simple test wire right off the battery to the coil to get the 12V. Then try to start the car to see if it fires up. If it does, you know where your problem is. The car will not shut off as long as the 12V test wire is hooked up, so you have to disconnect it to shut the engine down. If that does not do it, then the module would be my next guess, but in any case, you gotta have the 12V. I don't know how to test the HEI/module, but I believe if you do a web search there is a tutorial/instructions on how to do this which may save you a few dollars if the HEI/module is OK.

It could also be the ignition switch going bad and I would not rule this out either if it is the original. I had mine quit, but it gave me warning by sometimes working and sometimes not, then jiggling the switch and it would fire up, so I knew what it was as the contacts inside the switch do wear down. Make sure it is also not grounding out through a wire somewhere and that all your grounds straps are in place if the engine has ever been removed.

:thumbsup:


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## jodyB (Oct 2, 2016)

Thanks for the reply Jim,

Sorry, I forgot to mention I did try the wire from the battery to the + coil post. No luck. I am going to do a little digging to see how to test the module as an elimination step. However, the power to the coil would still need to be 12v regardless if the module is bad wouldn't it? 

My thinking (which has been proven to be occasionally flawed) is that the module wouldn't be engaged into the system once a spark was first sent into the distributor from the coil wire. I guess what is confusing me is that right now I am only getting 9.4v from the power lead to the + on the coil when the engine cranks? I no longer have a ballast hooked up to lower the voltage, so I don't know why I am only getting 9.4 at the positive post? I also think it should be 12V? The only thing between the battery and the positive post on the coil is the ignition switch? if I don't get 12v spark into the distributor I am not sure the module will get the power to engage the plugs with spark? is my thinking flawed?


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## Goat Roper (Oct 28, 2014)

The wire to the coil itself is a resistance wire so with electronic ignition you use it as a trigger wire for a relay that will put 12V to the coil when energized.
You probably burned up the unit in the distributor so you will need to replace it and wire in a relay.


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## jodyB (Oct 2, 2016)

Thanks Guys!!! I am going to test the Mod in the morning. if its fried I we put a relay in and a new unit. Let ya know what happens.


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## PontiacJim (Dec 29, 2012)

You may also want to read this as it may help: HEI Conversion


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