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Topic Review (Newest First)
04-01-2012 11:20 AM
Lramsey263 Disregard my previous post, I found a procedure to bypass the computer and it has fixed the problem, thanks for your help.
04-01-2012 11:06 AM
Lramsey263 I changed the module with a new one, still no spark, a couple of questions before I start going thru everything again...
1. What role does the Engine Computer play in the starting process if any? I checked the continuity from the the distributor plugs back to the computer.
2. Could the anti-knock sensor have any role in this problem? That is the only 7 wires that come out of the computer.
Thanks.
03-27-2012 06:37 PM
LATECH the only thing left would be the ignition module, that is if you are certain the rest of the components are good.
NAPA should be able to test the module, take them both down there and see.
03-27-2012 05:36 PM
Lramsey263 OK, I rechecked everything and to my ability it appears to be as I previously stated. What does this mean to me? When I hook a wire directly to the coil, I can get a spark when I touch ground, when I put a spark plug wire in seris with this setup, I can not get a spark. I also used a coil wire off a 67 Mustang to make sure I didn't have a bad wire but still could not get a spark.
03-25-2012 06:54 PM
LATECH
Quote:
Originally Posted by Lramsey263
I am restoring a 80 TA with 301 Turbo. I am not getting any spark to the plugs. I have replaced the ignition coil, rotor and distributor cap. I have done a resistance test on the pick up coil (I think I did it correctly).
Did you also look at the conductor for the bottom side of the coil, the little thing with the spring on it?
Also maybe it is making good spark and it is shorting through the rotor.Look for a bad spot under the tang of the rotor where the coil button touches it.
The system may be making spark and it is just not making it to the plugs.
For what its worth.
03-25-2012 06:47 PM
LATECH
Quote:
Originally Posted by Lramsey263
No, I measured the volts while the ignition switch was in the run position, not while cranking it...would that make a difference?
I never messed with the distributor so I can only assume the polarity on the pick up coil is correct. However, could the ignition coil be reversed? Would it make a difference?
Battery positive is from the same tab on the ignition switch when cranking as it is in the run position on your car. But the switch could have an issue so it is best to check it while cranking.
Assuming the polarity is correct, saying you havent messed with the distributor, then saying you measured the resistance of the pickup coil is contradictory. Not trying to bust your chops, but you were in there at the pickup coil. Are you sure you put it back in the right position.Maybe the wire broke when you were finished checking it. maybe you should take a second look.
Reversing the ignition coil wires in the HEI cap would be an obvious mistake, you would have to be trying real hard to put them in backwards.Did you check the ground wire out of the coil and the ground strap like in the picture?
making assumptions about circuit conditions is not a good solid way to do a diagnostic. test it check it , be sure, dont assume. That wastes everyones time. Once again not bustin chops , just trying to reinforce good testing, which will yield good results.
03-25-2012 04:12 PM
lmsport No, you can not ground the coil - as you for sure wont get any sparks.
You can run a ground jumper from the distributor body to the engine or the battery.
Measure the resistance of the dist body to the engine and make sure it is less than 1 ohm, preferably less than 0.1 ohm.
03-25-2012 04:01 PM
Lramsey263 I will give that a try, if I run the jumper from the + Battery, can I also run a jumper from the - Battery to the other side of the coil to ensure I do have a good ground?
I appreciate your help!
03-25-2012 03:56 PM
lmsport It might make a difference.
Without looking at a schematic, I cant tell you if the start source and run source of voltage are the same. Run a jumper to the coil hot and crank it.

I think if you have the correct pickup coil, the polarity is correct cause the connector tabs to the module are different sizes???
I havent loooked at a stock HEI in a few years so pardon my memory.
03-25-2012 03:47 PM
Lramsey263 No, I measured the volts while the ignition switch was in the run position, not while cranking it...would that make a difference? I never messed with the distributor so I can only assume the polarity on the pick up coil is correct. However, could the ignition coil be reversed? Would it make a difference?
03-25-2012 03:41 PM
LATECH the pickup coil polarity could be backwards.try reversing the green and white wires at the module.
Different GM lines use a different coil magnetic polarity , necessitating the need to reverse the color/connector/pin posistion . a coil for chevy will be reverse of what a pontiac will be.
03-25-2012 03:40 PM
lmsport
Quote:
Originally Posted by Lramsey263
Yes, I measured it with a voltmeter to the connector and also left the coil cover off the distributor cap and measured it at the connection on the coil itself.
You measured while the engine was cranking?

If you have voltage and a new coil, you must have a bad module. Or two.
03-25-2012 03:30 PM
Lramsey263 Yes, I measured it with a voltmeter to the connector and also left the coil cover off the distributor cap and measured it at the connection on the coil itself.
03-25-2012 03:26 PM
lmsport Thats a good value for the pickup coil resistance.
Are you sure its getting 12V to the distributor when the key is in the crank position? You can always run a jumper to the distributor straight from the battery.
03-25-2012 02:59 PM
Lramsey263 I tried your suggestion, cleaned the contact points for the distributor hold down and was able to get a good ground. The resistance is 785 to 800 on the pick up coil.
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