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post #9 of (permalink) Old 06-12-2019, 11:59 AM
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Location: Sedgwick, Kansas
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Originally Posted by wilson_ View Post
Thanks everyone; additional info requested is as follows:

Coup: Distributor is Mallory. No problems with PCV blowing out, but I haven't had it running yet either. It only fires for me. Plug wires are correct, and all cylinders firing; timing is close enough.

Matter: Yep, bowl is full of gaso. Pretty evident of vacuum problem which is why I tackled the valves. Could kick myself for not observing valves opening and closing prior to removal. I have soaked and scubbed carb twice and cleared all passageways, new gaskets, complete rebuild.

Chuck: My distributor doesn't have the advance vacuum valve on the stem; actually their is a fitting on the stem for the canister, but it is capped.

I'm going to mock up the heads and see what the valves say. Anyone know of a good lifter test besides watching the valves open and close? Any other ideas why she ain't suckn no gas down in her?
You won't always see any gas misting down the throat of the carb, even if you stand there and look (and if your car's not running right, this is a very bad idea. Ask my hair how I know.) However, when you move the throttle linkage (running or not!) the squirters should shoot a nice stream down the throat as you step on the gas. If it's not, you may have lost some of the tiny bits that live under the screw holding your venturii down - or, the squirter nozzles are clogged. I find that a stripped-down twist tie from a bread sack works great to get the crud out of them, in conjunction with some carb cleaner.

Don't go all crazy with making changes to everything. One thing at a time, or you will just end up going back to undo all the 'fixes' you have made. Since you've been working on the carb, and suspect vacuum leaks, let's roll with that first: Are you running a stock 2v manifold and is there a carb spacer under it? Sometimes the 4100s don't like to seal to a bare manifold, because there's not much surface area. They do better with the nice flat surface of a 2-hole spacer.

Is your PCV hose all hard and brittle? Does the check valve stop you from blowing hard through the valve cover end of it? (that can be a huge vacuum leak that's very hard to find, if it's stuck 'open'.) The valve should allow air to flow through the tube towards the carb when you blow gently, but if you blow hard, it should try to stop you.

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