Re: # 4 cylinder
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Home away from home
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Try plugging the drain line from the intake manifold for a minute and see if it picks up.
Posted on: 2016/10/18 11:36
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Re: # 4 cylinder
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Home away from home
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Drat - no difference
Posted on: 2016/10/18 13:07
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1938 1601 Club Coupe
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Re: # 4 cylinder
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Forum Ambassador
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A thought. IIRC, a few years ago someone posted a photo of a manifold where a hole had developed in the area of intake manifold below the carb where exhaust is directed when the riser valve is closed. On that manifold exhaust was able to get into the intake side. Don't remember the symptoms or know if a leak like that would only affect one cylinder unless maybe it was directed into one runner.
Posted on: 2016/10/18 13:26
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Howard
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Re: # 4 cylinder
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You say the compression is good, the other 7 cylinders are obviously receiving fuel/air mixture and firing normally so that would make me suspect an ignition failure - bad spark plug, distributor cap problem, etc.
Have you checked the intake manifold vacuum.
Posted on: 2016/10/18 13:42
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Re: # 4 cylinder
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Home away from home
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Vacuum is good - changed wire ,plug, cap and even a known good dist. Very Very strange.
Posted on: 2016/10/18 13:56
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1938 1601 Club Coupe
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Re: # 4 cylinder
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As you listen to the tailpipe while the engine is idling, is it obvious that 1 cylinder is not firing?
Posted on: 2016/10/18 14:36
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Re: # 4 cylinder
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Home away from home
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It does make a little puff puff sound but it always did that. I'm stumped as is a mechanic friend of mine
Posted on: 2016/10/18 14:48
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1938 1601 Club Coupe
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Re: # 4 cylinder
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Home away from home
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It would seem to me that the fuel charge is seeping away before it is fired by the spark plug. So I would be inclined to bring #4 up on the compression stroke and hold it to see how long the compression holds. If it dissipates faster than another cylinder, than a valve, head gasket, or intake gasket...Not Fun! I would check the intake manifold and gasket first. As odd as it sounds, a part of me wonders if there is a piece of junk in the intake manifold!Ernie
Posted on: 2016/10/18 15:43
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Caretaker of the 1949-288 Deluxe Touring Sedan
'Miss Prudence' and the 1931 Model A Ford Tudor 'Miss Princess' ![]() |
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Re: # 4 cylinder
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Home away from home
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One more thing I noticed that I forgot to mention. While looking at the valve lifters with the engine running one of the valves and it lifter (on #4) were rotating a lot faster than the all the others. Does that mean anything to anybody?
I really really don't want to pull the head on my beast.
Posted on: 2016/10/18 18:29
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1938 1601 Club Coupe
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