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1977 Exhaust Flutter

Old Aug 19, 2014 | 08:59 AM
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Default 1977 Exhaust Flutter

I noticed at idle the exhaust flutters. I did a vacuum test at the intake last night and noticed the reading bouncing quickly between 15 and 21. The same reading exists at acceleration. Does this sound like a sticking valve? I've looked at some of the reading examples and can't find any that are exactly like mine. Any other tests I can try?

Thanks!

Adam
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Old Aug 19, 2014 | 12:20 PM
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Start with the basics, how many miles on the plugs? have you checked them to see if one of the cylinders isnt firing correctly? How old are the wires, distributor cap and rotor, etc. Have you checked for a vacuum leak?
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Old Aug 19, 2014 | 02:08 PM
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Originally Posted by MelWff
Start with the basics, how many miles on the plugs? have you checked them to see if one of the cylinders isnt firing correctly? How old are the wires, distributor cap and rotor, etc. Have you checked for a vacuum leak?
I pulled the plugs and re-gapped them. They looked almost like new. The wires and cap appear to be almost brand new. I pulled each plug wire off individually and each one caused ticking when removed. What's the best way to check for a vacuum leak on these?

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Adam
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Old Aug 24, 2014 | 11:03 AM
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Originally Posted by ajacks87
I pulled the plugs and re-gapped them. They looked almost like new. The wires and cap appear to be almost brand new. I pulled each plug wire off individually and each one caused ticking when removed. What's the best way to check for a vacuum leak on these?

Thanks,

Adam
Some old school mechanics back in the day would use a plumbers propane torch, gas only not lit, and flow the gas near all vacuum leak areas and if the engine RPM increased, you found the leak. All vacuum hoses are potential leak areas due to cracking with age. Do this test out doors or at least well ventilated area.

Mike
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Old Aug 24, 2014 | 11:27 AM
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I would do a compression and leak down test.
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