360 Running Rough
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Joined: Dec 2001
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360 Running Rough
I posted eariler about my 1969 360 popping through the carb I ran some Marvel Mystery oil through the engine and ran it for 30 minutes and the popping has seem to gone away but my latest problem is the engine idles very rough and I am hearing what I think is a lot of ticking from the valve cover area. I replaced all of the tune up parts and timed it to 10 BTC. When I hooked a vacuum gauge up to the motor the gauge was fluctuating between 10in and 20in very rapidly while the engine was at an idle when I accelerated the motor the gauge would go up to 25 in of vacuum and would steady out quite a bit. I did a compression test and the readings were around 135 to 125. I am still at a loss could it be a vacuum leak somewhere or is it something worse? The vacuum gauge reading are confusing me a little bit. So any help would be great.
Thanks
Jason.
Thanks
Jason.
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Joined: Dec 2001
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From: Louisville,Ky.
360 Running Rough
You may want to pull the valve covers and look for a bent pushrod. The erratic vacuum sounds like a valve problem. It will build compression if you have 1 valve not opening but will miss and pop. It sounds like a possible intake valve that is not opening. Just a guess though. If all of the cylinders are pretty close on compression, then I would say that a burnt valve is unlikely. The ticking noise leads me to think it is a valvetrain problem. Either a puchrod or rockerarm. Good luck, let me know how it checks out. Oh, yeah. If pushrods and rockerarms look ok, start the engine with the valvecovers off and check to see that all 16 rockers are moving about the same distance. You could also have a cam lobe going flat. Jimmy 
360 Running Rough
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Joined: Dec 2001
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360 Running Rough
popping through the carb is indication of an open intake valve, and or a bent pushrod as mentioned. Something mechanically out of sinc causes the fuel to ignite (pop) outside the cylinder and through the carb
