I'm hoping the white smoke is not a blown head gasket.
CK5
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Can a rich mixture condition in a quadrajet cause white smoke?
- Thread starter wazzabie
- Start date
I may be lacking some wisdom, but the only thing I am aware of that makes white exhaust is coolant. Fuel burns black. Oil burns blue.
how long do you get white smoke ? has the engine been sitting for a long time ? Look for bubble in the radiator. From cold how fast does the upper hose have firm pressure ?
The engine has been sitting for a long time. I've started the engine occasionally about once every two years over the past 10 years and ran the engine for a few minutes. There was alot of white smoke the other day. Today I ran the engine and there was almost no white smoke. I refilled the coolant and looked for bubbles. I did not see any bubbles. Also I'm getting 45 on the manifold vac. The harbor freight gauge says that is within normal. Perhaps I have a rich mixture. I can see water on the end of my tailpipe dripping out. Now it is showing 42 on the manifold vac gauge which indicates late ignition timing.
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16.5 in vac and 18in vac. I realized the other numbers were not in inches.
Here are the specs for the engine/carb tuning.
Here are the specs for the engine/carb tuning.
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I wouldn't jump to head gasket just yet. 16.5 in of vacuum is not horrible. Adjust the air fuel for highest vacuum, then set idle speed rpm. Check for water in oil, if none and it's safe to drive, drive it.
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Did you add new fuel before it stopped smoking?
ld fuel will smoke white, how old was the fuel?
Did you add new fuel before it stopped smoking?
It was new fresh fuel. Non ethanol. I also have new fuel lines and a new fuel tank. The old fuel lines and gas tank were rusted.
To increase the vacuum should I turn the fuel mixture screws in or out? What would be a good vacuum reading?
This will be iterative, based on trial and error. Best to use a tach. Turn the screws a little bit at a time, whichever direction raises the idle speed. Then adjust the idle speed back down to the original set-point. Repeat this until you have the most vacuum possible.
(If you don't have a tach, but have a DMM, it may have a "Hz" mode that you can watch go up and down by measuring at the ignition coil power)
(If you don't have a tach, but have a DMM, it may have a "Hz" mode that you can watch go up and down by measuring at the ignition coil power)
Or maybe it could be wishful thinking. New engine time.
You can get a test kit from Napa for pretty cheap to check head gaskets.
I tested one of my vehicles a little while back. Thankfully no change in color - took that around the back to the exhaust tip and drew through some exhaust and the color did change, as a double check of the test itself.
I tested one of my vehicles a little while back. Thankfully no change in color - took that around the back to the exhaust tip and drew through some exhaust and the color did change, as a double check of the test itself.
Yes this is a good test. ^ Make sure the coolant in radiator doesn't get into the tool. A lower than normal level helps. Just want to sample air/gasses in cooling system.
I made two changes. I changed out the th350 vacuum module and I also turned the mixture screws out 2.5 turns from bottoming out. There is no longer any white smoke from the exhaust. I though I may have a bad head gasket but that is not the case. I did not see any bubbles in the coolant and the leak detector test was negative.
Good news
