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Discussion Starter #1 (Edited)
1966 straight six with auto trans. It was misfiring when cold, so I pulled the plugs and every one is fouled. There was black fluffy chunks on some of the plugs, and there was some oil mixed with gas on the threads when I pulled them. So I replaced the plugs and the brand new ones still misfire until all the blue smoke blows out of the tailpipe (a few seconds after startup.) Also, it has a harder time starting when the engine is warm. If it's burning oil, it's not enough that I have to add any between oil changes.


Any suggestions?
 

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Maybe a compression test is in order. Rings may be shot and your getting excessive blow-by?
 

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Sounds like your rings are gone and oil is fouling your plugs.
 

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If the smoke clears quickly and doesn't smoke again until the car has got cold/been sitting overnight it is more likely to be valve guides/stem seals. If it smokes on deceleration with closed throttle it is valve guides. If it was rings it would be smoking all the time.
 

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could be the valve seals. the stock rubber type will get hard over time and oil will ease by them. i'v never seen it happen but if the pvc were to get stuck open for a brief moment it could allow enough oil to get sucked into the intake to cause it to smoke on startup. just an added thought.
 

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Just a thought...... Pull your dipstick out and smell the oil. if it smells really fuelish? it's possible that your floats stuck, and washed down the cylinders?

Also.... If it is a ring, or seal problem, this should increase your crankcase pressure, So look for abnormal venting from your PCV hose, or Breather?

Good Luck., I hope it all turns out OK!
 

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Black, fluffy deposits can be gas fouling, caused by either running too rich or a defective ignition system. Oil fouling is usually wet and sludgy.
 

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Smokin'

1 other possible problem that is not oil related (engine oil). Check your modulator if you have an AT and see if it's bad. If it is, it's sucking trans fluid into the engine and it too, can cause problems!
 

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After all is done and checked and its just a normal worn out engine you CAN get by for a while by installing Non-fouler adaptors on your plugs-we used to use them years ago along with a plug in 1 heat range hotter than stock in the old six-bangers.
 

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Easy Stuf

As suggested above:
1) Do a compression test if it is OK..
2) Put on new valve seals ($15.00)
3) Put in 1 range hotter plugs

These are the easiest things to do. Most likely will fix it IMHO.
 

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Discussion Starter #12
so I was about a quart high on oil. Drained the excess out, adjusted my timing and it runs a lot better...hoping that the extremely retarded timing was causing lots of fuel to go unburned and fouled my plugs, and that the oil was burning on startup because there was too much of it. I'm still waiting to receive my valve seals, and I'll do them anyway once they arrive.

Thanks for all the help!
 

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so i was about a quart high on oil. Drained the excess out, adjusted my timing and it runs a lot better...hoping that the extremely retarded timing was causing lots of fuel to go unburned and fouled my plugs, and that the oil was burning on startup because there was too much of it. I'm still waiting to receive my valve seals, and i'll do them anyway once they arrive.

Thanks for all the help!
when you do your valve seals, make sure you don't let a valve slide down into the cylinder if the piston is at the bottom. You will have a mess then.
 

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I've had some of the same problems with the 6. In my case it turned out to be a bad fuel pump putting gas into the oil, thinning the oil so it washed past the rings.
 
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