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No Spark On My Small Block

Buddy67Lincoln

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Buddy67Lincoln Enthusiast

Buddy67Lincoln

Posted
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I have an '84 GMC Sierra with small block 400 with HEI. It shut down yesterday when driving and would not start. Pulled a plug to see if it would arc and it did not. I replaced the newer coil with a brand new one and still no spark. I had the control module checked at Advance Auto and it passed the test 3 times. I put it back together after cleaning all the plug prongs and still no good. I tested everything with a test light like the 'BAT' on the coil and that passed. The rotor spins when cranked so no bad gear pin or anything. The only thing left is the pick up wires going into the shaft. I wiggled the 2 wires that were there and they did not seem loose, but maybe could have broke at the pick up itself? Does that make sense!? Thanks for any help.

autopat Enthusiast

autopat

Posted
Posted

Thats where I would start, your pickup coil is probably toast. Instaed of wiggling them give them a good tug, and if they are still intact, check across the wires with a meter, if that comes up OK, check the fusible link at the starter, I've had them go bad before as well. Hope this helps.

 

Pat

Buddy67Lincoln Enthusiast

Buddy67Lincoln

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Thats where I would start, your pickup coil is probably toast. Instaed of wiggling them give them a good tug, and if they are still intact, check across the wires with a meter, if that comes up OK, check the fusible link at the starter, I've had them go bad before as well. Hope this helps.

 

Pat

 

Thanks. So far I have bypassed the ESC and had my control module tested a few times so I bought a pick up coil. I will check the fusible link as well. Thanks a lot! This problem has been driving me nuts for 4 days now

Buddy67Lincoln Enthusiast

Buddy67Lincoln

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just a thought but you checked to make sure your getting 12 volts to the distributor when ignition on right?

 

Yep. Tried to get a reading on the pick up coil and nothin so I checked my new one I bought to make sure I was hooking it up right and got a reading so bad pick up. My new delimma is pulling the distributor off and when I found TDC at cylinder 1...the rotor aimed at cylinder 6 instead! Guess someone installed it incorrectly and messed with the wires to get it running. Anyways, that where I am at now with it. Got to figure out how to pull the distributor and make sure I can get it back in correctly and fix the wires without screwing up. Thanks

I-H8-4Ds Enthusiast

I-H8-4Ds

Posted
Posted

I had this same problem a long time ago. After checking everything, I could not find what was wrong. Then I took a good look at my rotor (it was white). The plastic insulation had broken down and the spark was arcing through the plastic to the shaft underneath. It may be a longshot, but maybe this had happened to you too.

Buddy67Lincoln Enthusiast

Buddy67Lincoln

Posted
  • Author
Posted
I had this same problem a long time ago. After checking everything, I could not find what was wrong. Then I took a good look at my rotor (it was white). The plastic insulation had broken down and the spark was arcing through the plastic to the shaft underneath. It may be a longshot, but maybe this had happened to you too.

 

Thanks, I will take a look at it. Its a newer one and looked good when I examined it but did not look for that specifically so it cant hurt to check again.

mcreyaufmiller Senior Enthusiast

mcreyaufmiller

Posted
Posted

I had a brand new rotor and cap out of the box that were both bad, no visible signs of defect, just would not work. I replaced them and problem fixed. Make sure you are at 1 TDC (on Compression stroke), if I am not mistaken at if you are on 1 exhaust stroke, then 6 is TDC.

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