Carb question again

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statsystems
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Re: Carb question again

Post by statsystems » Fri Nov 03, 2017 4:44 pm

JDR Performance wrote:
Fri Nov 03, 2017 2:42 pm
The engine wouldn't run without vacuum below the carb. I would put a spacer with a vacuum port between the carb and manifold to check how much you have and look closely at the bottom of your carb and mounting gasket to see why it isn't seeing it at the port.

That's what I think. It can't run without a pressure drop.

I also looked closely at the gasket and the ports on the base of the carb. I wish I could post pictures. It's just a #54 Mr. Gasket open 4150 gasket.

I'm going to try Mark's idea to blow a bit of air back into the PCV valve port and see what happens.

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Re: Carb question again

Post by statsystems » Fri Nov 03, 2017 4:49 pm

F-BIRD'88 wrote:
Fri Nov 03, 2017 3:21 pm
Is there any vacuum at the 2 little fittings on the front of the carb at idle.?
One is full manifold vacuum other is ported vacuum ( no vac at curb idle
but some vacuum as you open the throttle some.)
Any vacuum at these spots?

Ya got me stumped now... ha ha

Both of your carbs are doing the same thing?
The BLP has just one manifold vacuum port at the front, and that's where I've been checking vacuum on that carb.

The ProForm has two vacuum ports. The outer one is manifold vacuum and the inner one is timed. I checked it off the manifold vacuum port.

Both carbs do the exact same thing. Neither carb has any airflow at the PCV port.

I've checked all around the carb base and all over the intake manifold and intake/cylinder head gasket and I can't find a leak. What blows my mind is the damn thing doesn't act like it has a vacuum leak, yet has no flow at the PCV port.

It's a good thing I don't smoke dope. If I did, the local dealer would be making a mint.

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Re: Carb question again

Post by lefty o » Fri Nov 03, 2017 4:54 pm

seems bizzarre that there is no vac. as previously stated there has to be a pressure differential for a carb to work. something dont jive, but i dont have an answer either.

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Re: Carb question again

Post by fdicrasto » Fri Nov 03, 2017 7:04 pm

How good does this car actually run? You mentioned rich cruise, lean tip in but it "runs good". What driving have you done and have you put some hard pedal to the metal test passes? What are some details of your ride? Based on this vacuum problem which should not exist I have to question if it can get down the road that well. Sorry if this sounds harsh but as previously stated, something seems weird here.

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Re: Carb question again

Post by Geoff2 » Sat Nov 04, 2017 5:43 am

I'm with Lefty, something not right. Engine has to create vacuum to run at idle & if no vac at the supposedly correct vac port, then maybe the port is blocked...

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Re: Carb question again

Post by statsystems » Sat Nov 04, 2017 11:22 pm

fdicrasto wrote:
Fri Nov 03, 2017 7:04 pm
How good does this car actually run? You mentioned rich cruise, lean tip in but it "runs good". What driving have you done and have you put some hard pedal to the metal test passes? What are some details of your ride? Based on this vacuum problem which should not exist I have to question if it can get down the road that well. Sorry if this sounds harsh but as previously stated, something seems weird here.

I had a weird situation with the tip in. For some reason, one of the power valve channel restricters had backed out and turned sideways in the hole. How that happens...I have no idea other than I may be using set screws that are too short. If that happens again I'll order some longer screws.

As for the vacuum issue I got sidetracked Friday, so I'm going out tomorrow and I'm going to blow some air in the PCV valve port and see what happens. I may take a video of it...but I can't even post a picture. Don't know how I'd ever post a video.

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Re: Carb question again

Post by F-BIRD'88 » Sat Nov 04, 2017 11:27 pm

You'd want to get a Youtube account and upload a video there.
Make it public and post a link to that video on www.Youtube.com

Post the video in a smaller more compressed video file format 144p max
so when people watch it it does not suck up all their data.
Raw video and pictures right out of your phone or camera is way too big.
Full HD video is not required.

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Re: Carb question again

Post by MadBill » Sat Nov 04, 2017 11:47 pm

statsystems wrote:
Sat Nov 04, 2017 11:22 pm
.. I'm going out tomorrow and I'm going to blow some air in the PCV valve port and see what happens...
Using lung power? That way you can better judge how open or otherwise the port is.
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

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Re: Carb question again

Post by af2 » Sat Nov 04, 2017 11:48 pm

Are you checking vacuum with the engine running???????? :)

Just kidding. Pull the carb and see why the port is closed.
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Re: Carb question again

Post by af2 » Sat Nov 04, 2017 11:50 pm

Just put a 6-71 with 500 cfm carters and the problem will be gone!!!
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Re: Carb question again

Post by statsystems » Sun Nov 05, 2017 12:27 pm

MadBill wrote:
Sat Nov 04, 2017 11:47 pm
statsystems wrote:
Sat Nov 04, 2017 11:22 pm
.. I'm going out tomorrow and I'm going to blow some air in the PCV valve port and see what happens...
Using lung power? That way you can better judge how open or otherwise the port is.

I'm not real excited about putting a hose in my mouth but I guess I can. I was going to use shop air.

Damn this thing. And it snowed last nite and it's snowing now. I'd ask what else can go wrong but I'm chicken

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Re: Carb question again

Post by MadBill » Sun Nov 05, 2017 5:28 pm

Just remember to blow, not suck...
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

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Re: Carb question again

Post by jmarkaudio » Mon Nov 06, 2017 9:17 am

Blow gun and air hose...
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Re: Carb question again

Post by statsystems » Mon Nov 06, 2017 1:14 pm

MadBill wrote:
Sun Nov 05, 2017 5:28 pm
Just remember to blow, not suck...

Dammit bill..........

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Re: Carb question again

Post by statsystems » Mon Nov 06, 2017 1:15 pm

jmarkaudio wrote:
Mon Nov 06, 2017 9:17 am
Blow gun and air hose...

That's what I'm going to do.

I'm going to to it a bit later today.

I'm also going to pull the carb back off and I'm going to lay the gasket on the carb and see if it's blocking the hole.

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