86 HEI no spark

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Knep115

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Hei distributor, 12V coming in, nothing coming out. I have replaced the cap, coil, module, rotor, button...checked ground strap, cant get any spark. The rotor does turn while cranking. I am stumped, any help is appreciated! Even put a new 12v pigtail on it.
 

PrairieDrifter

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Check the wires in the distributor for the ignition module. Probably pinched or broke one.
 

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Check the pickup coil. Should have around 900 ohms across it.
 

Knep115

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What is the best way to test it?
 

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What is the best way to test it?
To test the coil for Ohms , you would need a volt, ohm meter. I've had the pick up go bad it's the part that reads the signal from the reluctor ring when it spins.
 

1lejohn

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Those two small wires are known to become brittle and break…
 

Ricko1966

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86 should have knock sensor ignition. If the controller goes bad it will create a no spark condition super easy to check with just a piece of wire. Unplug the 4 wire connector at the distributor. Make a jumper wire to jump terminals A and C I believe green and black? I'll see if I can verify and post back anyway the jumper will bypass the control unit. Then you can run with it jumper while you source a control unit,or not. Some people ate perfectly happy with no knock sensor some are not. You can actually read about @SirRobyn0 year long adventure trying to run no knock sensor. I was not happy without mine. I'll double check bypass procedure BRB. Yep it's A and C Black and Green pics for illustration. You can just use a piece of wire for testing.
 

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Knep115

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UPDATE: Ricko, this is an aftermarket crate 350 with HEI, no knock sensor....So I have now replaced the cap, coil, rotor, button, 2 modules (3 total), the pig tail from the module to the distributor, and a new pig tail for the batter, currently no tack. I replaced the pickup coil today, got everything put back together, and still NO SPARK! I am going to recheck ground, but I am at my whit's end here!
 

Ricko1966

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UPDATE: Ricko, this is an aftermarket crate 350 with HEI, no knock sensor....So I have now replaced the cap, coil, rotor, button, 2 modules (3 total), the pig tail from the module to the distributor, and a new pig tail for the batter, currently no tack. I replaced the pickup coil today, got everything put back together, and still NO SPARK! I am going to recheck ground, but I am at my whit's end here!
I'd check continuity on all wires in the distributor,and cap. A wire broken in the jacket can be a real head scratcher. Flex tge wires while watching your meter. I'm suspecting ones open. Just thought of 2 more things disconnect power at the cap,run a jumper from the battery+ or alternator B+ to dist cap try to start it. Verifying you have 12v when cranking,also make sure distributor is actually turning while cranking .
 
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Knep115

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I'd check continuity on all wires in the distributor,and cap. A wire broken in the jacket can be a real head scratcher. Flex tge wires while watching your meter. I'm suspecting ones open. Just thought of 2 more things disconnect power at the cap,run a jumper from the battery+ or alternator B+ to dist cap try to start it. Verifying you have 12v when cranking,also make sure distributor is actually turning while cranking .
I have replaced all the wires inside the distributor, and a new pigtail coming from the battery, and the one from the module to the cap with the resistor...and it does turn while cranking...
 

Ricko1966

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I have replaced all the wires inside the distributor, and a new pigtail coming from the battery, and the one from the module to the cap with the resistor...and it does turn while cranking...
It doesn't have one coming from the battery to the cap it has one from the harness to the cap. Disconnect it make a jumper from the battery + to the cap andctry to start it. If it starts you are losing 12v to the distributor in crank position. You will have to remove jumper to shut the engine off,if that's the problem. You replaced every single wire in the distributor? There isn't one in there at all that was there before the problem started?
 

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