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| Too much Vacuum? PCV pinned https://slantsix.org/forum/viewtopic.php?t=35073 |
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| Author: | ceej [ Tue Apr 28, 2009 4:48 pm ] |
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Actually that's part of why your going to need the larger value. When you start pushing on the pedal, the vacuum goes south in a hurry. You have to beat it to the punch to keep the mixture from going lean. If you were drag racing, it wouldn't matter. A near Zero vacuum at WOT except when on the brakes. When you need a smooth transition to power with small changes at the pedal, you need to bring the mixture rich earlier. Don't mess with the 8.5 PV, go straight to a 10.5. Your going to have a minimum 17" HG on idle, unless something has been changed in there. Anything less than 19" HG isn't healthy. What jets were in the primary? CJ |
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| Author: | tony h [ Tue Apr 28, 2009 5:44 pm ] |
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I read your post AFTER I finished. Like an ass, I didn't think to look. That's two days in a row I meant to look. Monday night when I got home from Work we pulled the carb. took off the Bowl and was hoping to see a glob of something come out. I should have looked at the Jet # when I took them off and sprayed them. I can look with the Carb on the car so No biggy. I'll post back when I have some details You are proposing to go smaller on the jets for all around better gas mileage but a quick kick in the ass when accelerating by using a higher vacuum PV? Thanks again |
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| Author: | tony h [ Sun May 03, 2009 2:16 pm ] |
| Post subject: | Ok now a leak |
Refresh: Holley 4160-8007 4 barrel Replaced a blown Power Valve. The Power valve was the flooding/Vacuum issue for sure. After changing the Valve the car is happy... with one exception. What would make gas leak into the Intake manifold after turning the car off? The gaskets at the Bowl and Metering Block came off clean so I reused them.. Could they cause a leak INTO the carb and down the manifold? With the car warmed up, Turn it off and look at the barrels you see steaming/ vapor and the smell of gas. What kind of confirms this leaking into the manifold is .. The car starts up great first thing in the morning. It also starts great after driving and restarting about 1 hour later. It's the quick shut off and restarts that the car has a very hard time starting...like it's flooded. Yes the gasket was put on the Power valve when we installed it. We changed nothing else so i'm thinking maybe gasket at the Metering Block but I don't know enough to say that gasket could cause a leak down. |
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| Author: | ceej [ Sun May 03, 2009 2:43 pm ] |
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Boiling fuel off from the bowls is fairly common at shutdown. Gasoline will boil below 100°F Any raw gasoline in the plenum will look like a fog due to heat. Look into a phenolic spacer. Some folks have had luck with them. CJ |
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| Author: | tony h [ Mon May 04, 2009 5:59 am ] |
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Prior to teh Power Valve being replaced, the car would start with just the tap of the key after it was warmed up. Now it appears to flood and the Pedal has to be held down to clear it so it starts. Even though this carb was never set up correctly , this is a new issue. I understand the boil off but It should be happening when the car was running and then just turned off. I didn't mess with Float hieght I ddn't do anything other than switch oyt the PV. Something I did notice while we looked at this quick shutoff flooding was Vacuum. It seems that the most vacuum ( about 19) is when I have the adjustment screws about 1/4 turn out. It's always been like that. |
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| Author: | 65Dodge100 [ Mon May 04, 2009 10:15 am ] |
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The inlet needle and seat could be leaking. Danny |
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| Author: | tony h [ Mon May 04, 2009 10:38 am ] |
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Quote: The inlet needle and seat could be leaking.
This is the Needle valve that the Float closes??Danny Like, if the Float was adjusted too high, would it do the same thing? Maybe when I took teh bowl off and layed it on it's side to replace the PV something got shifted so it doesn't close right? I can't imaging that but it's worth a look. |
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| Author: | 65Dodge100 [ Mon May 04, 2009 5:04 pm ] |
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Quote: This is the Needle valve that the Float closes??
That’s the one. I was thinking more that it just got old and stopped sealing or got some crud on it but jangling it around probably wouldn’t help much either. Like, if the Float was adjusted too high, would it do the same thing? Maybe when I took teh bowl off and layed it on it's side to replace the PV something got shifted so it doesn't close right? I can't imaging that but it's worth a look. Looking at it probably won’t tell you much unless it has a big chunk torn out of the end or something. If the carburetor leaks into the manifold after shut down, on a cold engine, and stops about the time the pressure is gone from the fuel line, would be a pretty good indication. Danny |
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| Author: | tony h [ Sat May 09, 2009 7:10 am ] |
| Post subject: | Found the problem |
Even though the 'fog' was coming up from the Primary side, We had time to look at it last night. as soon as you turn the engine off, the Butterflies on the secondary side got wet. After taking off the secondary side bowl and seeing nothing obvious, I grabbed a can of carb cleaner and spray any orifice I could find. One of the 4 air intakes by the Pump Discharge Nozzle ( Squirters) was plugged. That stupid little clog must have created vacuum or pressure enough to cause this problem, Blew it clear , put the bowl back on and we are good to go. Thanks for hanging with me |
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