jw1955buick

Tuning ‘55 322 issues

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Ok, I stink at tuning, always have, every old car I ever had ran too rich and was hard to start, this one is no different

whats been done: rebuilt 322 with some type of RV slightly lumpier than stock cam, no info available, rebuilt carb, new coil, cap, plugs, wires, points, condenser, fuel pump, vacuum lines

the rebuild was 8 years ago and driven very little because of electrical issues that were never resolved, something draining the battery 

so I rebuilt the carb recently, replaced most ignition components, checked the gap in the points, timed it to 5 degrees, mixture screws out one turn, problem is it still runs rich and fouls the plugs, is hard to start when cool even with choke closed and seemingly working, sounds like a slight miss or vacuum leak

so compression is good and consistent, put a vacuum gauge on the port between the mixture screws, plugged the vacuum advance on dist, warmed up the engine and the gauge is showing 28 steady but when I kick down the throttle to around 500 rpm the gauge goes to 8 and stays there unless you get back in the throttle, I get no real change in vacuum by moving the dist unless I move it pretty far,  mixture screws make no difference in idle even if turned all the way in

seems like a vacuum leak from what I’ve read but I can’t figure out where it would leak at, checked all hoses and fittings 

the plugs always seem to be fouled so I feel like I’m in some time loop that I can’t get out of, don’t know if that port in the carb is the right place to measure vacuum but I don’t know where else you’d put it unless you drilled a fresh hole in the intake 

 

help please 

Edited by jw1955buick (see edit history)

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If the idle mixture screws have no affect then most likely the passages are clogged

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You must have some other vacuum port somewhere. Got vacuum wipers?

 

If the port you are connected to is the one for the distributor, it is probably not going to supply vacuum at idle.

 

 

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So the vacuum source for the distributor is a nipple at the base of the carb between the mixture screws, this is how I inherited it.

1  is this the factory vacuum source location for this setup 

2. If not, then what? And how and exactly where would you obtain the right source of vacuum to put a gauge on it?

 

it does have vacuum wipers with a line to the bottom of the two part fuel/vacuum pump2A9CE867-5FFE-4FB3-A1FF-1A025349A587.thumb.jpeg.ff095dbc2acfaa9adb73a5123686ecb2.jpeg

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Going out on a limb here, but, see that turquoise pipe threaded into  fitting threaded into the intake manifold just under the black vacuum hose in the picture? That is the vacuum source to the fuel pump vacuum section, which in turn provides vacuum to the wipers.

 

No need to plug the vacuum port on the vacuum advance, when the hose is disconnected. It is the hose or the port on the carburetor that needs to be plugged, as it should have vacuum on it at some point in time.

Edited by Frank DuVal (see edit history)
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Frank, that makes sense, so where should I splice in the vacuum gauge?

 

also I blew air through every tiny idle circuit hole I could find when I rebuilt the carb, pump, fuel line, tank all clean on start up, glass filter bowl is clean, no sign of any sediment anywhere 

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14 hours ago, 1956322 said:

If the idle mixture screws have no affect then most likely the passages are clogged

 

1 hour ago, 1956322 said:

What speed is it idling at?

If idling too fast the mixture screw have no effect...try again at 500 rpm.  Study that carter(?) carb in the service manual; blowing will do nothing if deposits are stuck...needs to be soaked!

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I did all that, total carb soak and rebuild per shop manual, I did everything but pull the shafts and remove butterflies, used the kit from CARs, it's possible that a piece of something is in there of course but unlikely considering that I went through the entire fuel system. 

It's improving as I go, it now at least stays running at 500 just not smooth, installing clean plugs over and over not knowing how quickly they foul and affect the idle, as always, it smooths out for the most part with increased throttle.

 

Any thoughts on choosing to time for max vacuum vs timing at the 5 degree mark per the manual? Pros? cons? terrible idea?

 

What's the original location for the distributor advance vacuum source? Pictures??

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13 hours ago, jw1955buick said:

2A9CE867-5FFE-4FB3-A1FF-1A025349A587.thumb.jpeg.ff095dbc2acfaa9adb73a5123686ecb2.jpeg

 

This is the carb you soaked and rebuilt?

The rubber tube should go to the vacuum advance.

I time all of my nailheads at 7* btdc at 350 rpm; you should an additional 10* when you raise the rpm (from the mechanical advance) and an additional 10* from the vacuum advance when connected

Check the dwell when running and at different rpm.

What brand and plug are you using?  Autolite  85 will serve you well.

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C4CCA625-1F78-4900-B9E0-4C23616D0C5C.thumb.jpeg.256192065e6638dc5b307e041ae97107.jpegHaha! I knew someone would point that out! that's the before picture.

 

Have a set of those NGK's that guys on here are running and some 45 or 44r's from CARs, can't remember the exact number

Edited by jw1955buick (see edit history)

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If the engine is running rich, why the concern about a plugged carburetor passage???

 

When the engine is totally warm, is the choke butterfly completely open (vertical)?

 

Fuel pressure at the carburetor?

 

Cannot tell from the picture: does that carb have the idle vent, and if so, is it functioning correctly?

 

Condition of grounding strap to engine block, and/or body?

 

Are the new wires resistor (carbon) or copper wire?

 

No offense meant, when you did the rebuild, did you get the pump discharge check valve in the correct spot?

 

It is possible you have multiple issues: (1) the rich idle, and (2) the hard start cold.

 

Jon.

Edited by carbking (see edit history)
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All things point to the carb. Specifically no change when the mixture screws are all the way seated.  With that said, is it possible a check ball or small internal piece was missed when rebuilt?  I say this because I have turned over carbs when working on them only to find a mystery check ball on the work bench.  

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I am just going to pipe in here. I had similar issue of running rich. I rebuilt the carb and issue gone. Not saying that is your problem but did you use compressed air to blow out all the passages after soaking the carb body in cleaner?  Also, whoever last dealt with my carb had the choke incorrectly set. You need to abide by the shop manual and set everything correctly.

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It may be the carb, it may not be.

 

As old-tank pointed out in an earlier post; if the engine is idling too fast, the idle screws will do nothing. One can screw them all the way in, or take them out and put them in one's pocket, there will be no change.

 

Either there is too much fuel, or not enough spark; tests will determine which it is.

 

Too much fuel could be caused by excessive fuel pump pressure, or the choke not going completely off, or a sunk float, or a missing accelerator pump discharge check valve, or maybe something else.

 

Too little spark could be caused by the new wires being carbon, or a defective ground through the ground strap, or maybe a defective voltage regulator, or?

 

Of course, if the consensus is a defective carb, I know a really good source for carb kits ;) I just don't believe the OP has exhausted enough possibilities to rebuild a previously rebuilt carb.

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So I’m not a good carb rebuilder apparently, I’m not getting a good squirt of fuel when actuating the throttle linkage, I’ll get one squirt and not a good one then bubbling and dribbles 

when it’s warm and you try to start it, acts like it’s out of gas so fuel is not getting in steadily for sure 

I found my float level is too low so work to do there, also is there supposed to be a spring under that vacuum piston that controls those metering rods? That T shaped rod bar is all the way up all the time with that spring underneath it, that’s how it was when I took it apart so I put the new provided spring back in there, something about it doesn’t seem right, that little hook on the accelerator pump shaft seems unnecessary with that spring in place 

I realize these are all very basic questions, I’m trying to learn this stuff 

 

and there’s plenty of fuel in the glass bowl the whole time so I don’t think it’s fuel delivery issues to the carb

Edited by jw1955buick (see edit history)

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13 hours ago, carbking said:

One can screw them all the way in, or take them out and put them in one's pocket, there will be no change.

 

When Detroit switched to downdraft carburetors the dealer network service manager requested lots of screws and adjustments for the carburetor. Lots of them right under the owner's nose just tempting him.

 

I would make sure I got it running on the idle circuit. You can do that by looking down the throat of the carb when it is running and making sure fuel isn't dribbling onto the throttle plates. Close the plates until that stops. If it doesn't stop, address the level issue. If it does stop at least you will be on the idle circuit and there's not much to scrutinizing that.

 

Wasn't there an initial drill bit size to use as a gauge to preset the throttle plate opening?

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1 hour ago, jw1955buick said:

So I’m not a good carb rebuilder apparently, I’m not getting a good squirt of fuel when actuating the throttle linkage, I’ll get one squirt and not a good one then bubbling and dribbles 

when it’s warm and you try to start it, acts like it’s out of gas so fuel is not getting in steadily for sure 

I found my float level is too low so work to do there, also is there supposed to be a spring under that vacuum piston that controls those metering rods? That T shaped rod bar is all the way up all the time with that spring underneath it, that’s how it was when I took it apart so I put the new provided spring back in there, something about it doesn’t seem right, that little hook on the accelerator pump shaft seems unnecessary with that spring in place 

I realize these are all very basic questions, I’m trying to learn this stuff 

 

and there’s plenty of fuel in the glass bowl the whole time so I don’t think it’s fuel delivery issues to the carb

 

Sounds like a carb issue from your description.  There should be a healthy squirt of fuel from the accelerator pump if the correct accelerator pump was installed.  If the float is low there is an issue certainly.  If I recall correctly, yes, there is a spring under the metering rods that keep them up.  If there is a hook there is a reason for it.   The T shaped bar(metering rod) can be installed backwards.  I know cause I done it.   The carb needs to be gone over again from the sounds of it.       

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This is a Carter 2 barrel. Would think the set up of the meter rods is the same as the big brother Carter you have.   There is a hook protruding that needs to be on the correct side.  Like I said, I installed mine backwards.   This picture saved my bacon in getting it installed correctly.aYjOtLE.jpg 

 

   

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Ok, so metering rod situation is correct 

seems like I need to go back over all the adjustments again from start to finish 

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Quote: ""I’m not getting a good squirt of fuel when actuating the throttle linkage, I’ll get one squirt and not a good one then bubbling and dribbles 

when it’s warm and you try to start it, acts like it’s out of gas so fuel is not getting in steadily for sure"

 

Could be a function of the pump check valves not working correctly, a modern non-leather accelerator pump that has already failed in modern fuel, pump cup leather incorrect size, or "turning upside down". The check valves not working correctly can make the engine run rich all of the time.

 

Quote: "I found my float level is too low so work to do there"

 

This is going to make the engine run very lean, if at all.

 

Quote: "also is there supposed to be a spring under that vacuum piston that controls those metering rods?"

 

Yes, the spring counter-balances vacuum. When the engine is off, the spring pushes the piston up. When the engine is running, the engine vacuum pulls against the spring, and the two working in conjunction control the height (therefore the metering step) of the metering rods in the jets. The higher the vacuum, the lower the rods are located in the jets (on the thickest part). When the vacuum goes to zero under wide-open-throttle conditions, the spring pushes the linkage and the rods up, and the rods will have the smallest diameter sticking into the jet.

 

As old-tank mentioned, the factory service manual is a good place to look for understanding. Also, a diagram FOR YOUR SPECIFIC CARBURETOR, from the factory Master Parts Book. If you got a generic set of instructions with a generic diagram in the kit, place it in your parrot cage (I can't spell parakeet) where it belongs! If you still have outdoor plumbing, it can be used in lieu of the Sears & Sawbuck catalogue!

 

Factory Carter literature is also quite useful, if you can find the page FOR YOUR SPECIFIC CARBURETOR.

 

Jon.

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Yes, definitely sounds like you will need to pull it and start again. Study the shop manual or read the relevant 'Hometown Buick' webpage for the carb. This will be especially important for the choke settings. You may also like to see if you can find youtube video of a rebuild for the Carter as that will assist. Compressed air to clean out every passage after soaking in a good carb cleaner. Not sure about the Carter but the Rochester has apparently 3 different accelerator pump diameters so make sure you have the right sized replacement as you won't get good fuel delivery if there is insufficient seal.

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Also floats have to centred in the bowls or they can catch and hangup. I found the rebuild video on youtube video was especially helpful with all this.

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