Number eight spark plug not firing

1988 CHEVROLET 1500
625,340 MILES • 5.7L • V8 • 2WD • AUTOMATIC
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GLIDERBOY19
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I changed the distributor, wires and plugs after having an intermittent skip in the engine. The old distributor was in bad shape. After completing the install I cranked the engine and the skip was still there all the time. I checked the compression on #8 and found it good. Tested with a separate plug and plug wire and found no spark at #8. Suspect the ESC or ECM. What might be the problem?
Jul 22, 2019 at 4:55 AM
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ASEMASTER6371
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Good afternoon,

What was the compression?

If you installed a new distributor and have no spark to 1 cylinder, then something is wrong with the distributor. What kind and where did you buy it?

The ECM has no involvement in spark to number 8.

Roy
Jul 22, 2019 at 5:32 AM
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GLIDERBOY19
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Bought the new distributor at O'Rielly auto. The old one did the same thing.
Jul 22, 2019 at 6:01 AM
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ASEMASTER6371
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Did you set the plug on the manifold to be sure there is no spark?

It does not make sense for not having spark on 1 cylinder with all the resr firing.

Is the wire grounding anywhere?

Roy
Jul 22, 2019 at 6:05 AM
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GLIDERBOY19
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Compression on #8 was 150lbs. This engine has 92,000 miles on it. The problem began as intermittent.
Jul 22, 2019 at 6:05 AM
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GLIDERBOY19
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Tied the test plug to a good ground. Got the same response.
Jul 22, 2019 at 6:07 AM
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ASEMASTER6371
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Did you change the cap and rotor?

Roy
Jul 22, 2019 at 6:11 AM
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GLIDERBOY19
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Yes. Changed the rotor and cap. Also new distributor module.
Jul 22, 2019 at 6:21 AM
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ASEMASTER6371
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A new module should have come with the distributor.

None of this makes any sense. You have changed all the components with no result in spark for 1 cylinder.

Does the shaft in the distributor have any lateral play?

Roy

Jul 22, 2019 at 6:24 AM
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GLIDERBOY19
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No.
Jul 22, 2019 at 6:30 AM
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ASEMASTER6371
  • ✓Experienced Mechanic
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Okay, something was missed somewhere.

Start over and recheck everything. Check the wire with an ohmmeter and tell me the resistance.

Roy
Jul 22, 2019 at 6:34 AM
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