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a past post, revisited
Posted by: corvairdoug ()
Date: March 06, 2022 11:55AM

Well, I need some guidance gurus. 140, PG, Fairly fresh engine rebuild, carbs were rebuilt about 10 years ago, secondaries are on but not hooked up. Car has always used a lot of fuel. Last time I drove it, after a long rest, and the right bank never stopped smoking whitish smoke. It ran fairly rough most of the time, Usually it smooths out a lot after it's warm. Drove it about 5 miles, got out, right bank smoking, put my hand over tailpipe, and it got a fine mist/glaze of gasoline. Did my errands, drove it home, and it didn't want to stay running at red lights. The smell of gas was fairly apparent. It used almost a quarter tank in the 10 mile trip.
I hooked up a Harbor Freight fuel pressure tester to the right carb by "teeing" in to it's fuel input line. Started the car, and once it idled, the tester read 8lbs, which sounds like a bad fuel pump to me. Am I right? If so, who has the best replacement? Also, I wouldn't be opposed to an electric one, if it doesn't rattle the whole car like a machine gun. I had one on a Vega in the 80's, and the vibration was unbearable. I also looked down into the carbs at idle, and saw no fuel dripping or spilling.
I'm curious, if it is the pump, why only smoke from the right bank?
Thanks Vair friends....

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Re: a past post, revisited
Posted by: TheRealHip ()
Date: March 06, 2022 12:49PM

I think yer fuel pressure is a little high. People here smarter then me will tell ya....

66 crown v8

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Re: a past post, revisited
Posted by: 66vairman ()
Date: March 06, 2022 01:10PM

Over the years a LOT of good information has been posted here about carburetor issues.

That said ---- knowing WHAT YEAR the carburetors are on your car are will help (the were revised to some degree EVERY year).

Carburetor fuel pressure is 4-5PSI. Your pump pressure is too high at 8 PSI (known issue).

When a carburetor was rebuilt makes little difference. I've seen carburetors rebuilt, then the the car sits for a year and the carburetors are all gummed up and need another "rebuild". BTW - most "rebuilds" are just cleaning the carburetor and installing new gaskets. After all this time the floats need to be tested, loose carburetor shafts replaced, etc.

You indicate a LOT of fuel is going into the engine. Not good as it washes the oil off the cylinders and can ruin the cylinders and pistons. I would NOT drive the car until you fix the excess fuel consumption issue.

Note white smoke can be excess fuel, and it can also be PG fluid getting into the balance tube from the PG modulator valve. Inspect the hose from PG to balance tube for transmission fluid - it should be dry.

Once you post what year carburetors you have, then folks can make more suggestions.

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Re: a past post, revisited
Posted by: vairmech ()
Date: March 09, 2022 03:38PM

Have you looked down the throat of the carbs to see if any are putting excess fuel through it? Even if you can't see it you can hear when it drips because it will make like a slurping sound. Even though the carbs were rebuilt are all the parts inside? I once had a set of carbs that didn't have the enrichment needle installed!

Also what size are the main jets?

It has been mentioned but you need to check the vacuum modulator. I have never been able to just pull the hose and know for sure, I always remove the modulator and try to dump it out. If anything red comes out it is bad!

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: a past post, revisited
Posted by: Frank DuVal ()
Date: March 09, 2022 07:40PM

Several threads on here about cutting a coil off the spring inside the fuel pump (THE part that makes the pressure) to reduce fuel pump pressure.

Frank DuVal

Fredericksburg, VA

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Re: a past post, revisited
Posted by: playerpage ()
Date: March 10, 2022 08:03AM

I stuck a fuel regulator in-line to the carb on mine. I'm not running mechanical, but perhaps it is a solution someone can use.

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Re: a past post, revisited
Posted by: corvairdoug ()
Date: March 10, 2022 07:21PM

Ken Hand, yea, I looked down the carbs while running, looks clear, no fuel splashing or dripping or anything.
As for the main jets, I don't remember the exact size, it's been a long time; I think I went one or 2 sizes over stock.

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Re: a past post, revisited
Posted by: vairmech ()
Date: March 12, 2022 05:26AM

Frank DuVal Wrote:
-------------------------------------------------------
> Several threads on here about cutting a coil off the spring inside the fuel pump (THE part that makes the pressure) to reduce fuel pump pressure.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I have never had an issue with Rochester carbs, only the finicky Carter YH on the turbo engines.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com



Edited 1 time(s). Last edit at 03/12/2022 05:27AM by vairmech.

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Rebuilt 65 Corvair carburetors throttle shaft problems
Posted by: Mark Hessler ()
Date: March 27, 2022 10:57AM

Hope someone can shed some light on this: I purchased a set of carburetors from a reputable vendor I've used in the past. When I installed them, I could not get it to idle. I found that the throttle shafts are sucking air around them, making idle almost impossible. I reported this to him and he said they were within specs when he re-built them. I have no idea how to verify this. What is the solution to this problem? Are there bushings? Can the shaft holes be so wallowed out that the carbs are unusable? Does anyone know of a fix; I don't think I'm going to get anywhere with the vendor,(I tried), nice guy, but getting up in age apparently and forgetful.

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Re: a past post, revisited
Posted by: Vairismo ()
Date: March 27, 2022 04:07PM

Mark Hessler,
Usually replacing the throttle shafts with new ones should solve that issue. The carburetor body is harder than the shafts. Typically it is the shaft that wears.
Good luck!

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Re: a past post, revisited
Posted by: red monza ()
Date: March 27, 2022 06:04PM

I have seen white smoke many times...it was always a bad transmission modulator with a split diaphram letting the engine suck transmission fluid into the engine, hence the white smoke. I bet if your check your trans fluid, it will be lower than your last reading. By the way, I have two brand new ones I bought from Rafee before he moved to Europe. You can get one from Clarks...I am not trying to sell mine but if they are out of them, I can help you out.By the way, you can block the line going to the transmission and the smoke will go away but probably will not shift but that is one way to confirm it needs a modulator.

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