engine miss

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Joined
May 26, 2013
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Location
michigan
My Car
1973 red convertible 351 4 V
My engine has a miss that I can't figure out. I have new autoilite 42 sparkplugs and new ignition wires. I also have a 1406 Edelbrock carburetor. I just changed the fuel filter. I was going to play with the timing next. Is there something else I should look at?. My car is stock except for the carb.

John J

 
If it is a constant miss, (dead miss) I'd move the inductive pickup of the timing light to all 8 plug wires to see if spark is occurring reliably on all 8 cylinders. If you have consistent  spark at all 8, I'd suggest doing a compression test to find the bad cylinder. Once you identify the bad cylinder, pull the valve cover on that side and check to see if something has gone wrong with the pushrod, rocker arm, valve spring, etc. If that is all good, do a leak down check to determine the source of the compression leak (intake, exhaust, rings).

If it is an intermittent miss,

 
Did you check/set the gap on the new plugs? What did the old plugs look like?

 
With car running, pull 1 wire at a time off the cap, when you hit the wire that when removed does not change the engine idle, do a compression test

 
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