Is it the carburetor this time?

While my convertible is at Mike's (Buick5563) shop for repaint, he has left one or another of his cars at my shop for maintenance. The first was his 55 Special to service the factory a/c. He let me experiment with a different refrigerant (diflouroethane) with good results.

Next was his 55 Century wagon (cross country traveler aka Texas Road Warrior). The first issue was the slobbering rear main seal http://forums.aaca.org/f162/how-stop-rear-main-seal-leaks-344800.html.

Next was the horns: two problems --- first was the crusty horns that sounded like a constipated Chihuahua. They were cleaned and tuned to have a nice loud discordant sound (half step with digital tuner). The other horn problem was the contact on the steering shaft which is a straight forward job of 10 hours and only requires a handful of Motrin and Tylenol and whole bunch of choice words.

The next issue which is the subject of this post was the very poorly running engine. History: all ignition service items replaced (points, condensor, cap, rotor, plugs and wires); carburetor (WCFB) rebuilt and opened soon after rebuild to re-set the floats and rods. All that was 5,000 miles ago and the performance was flawless. About 1,000 miles ago the idle started to get rough, there was hesitation. This progressed to where it would not run if the idle was below 1,000 rpm, died if put in gear (dynaflow) or if the a/c was turned on. Checks revealed no vacuum leaks, everything was tight, idle mixture screws had little or no effect. It ran smoothly at higher speeds.

What to check next or just add fuel injection like Ben did http://forums.aaca.org/f118/1950-special-modified-12v-efi-345328.html or look for an Edelbrock carburetor like VickyBlue did http://forums.aaca.org/f162/edelbrock-1406-conversion-333493.html .

Suggestions? (to be continued...)

Willie

Ooh, I know, I know!!! Pick me.....

Ummmmmmm............diaphram in the fuel pump going south? Matt

Malfunctioning vacuum advance?

Manual fuel pump has been removed. Electric fuel pump only.

JD has part of it.

Still could be carb?

How about debris from the manifold heat passages clogging up the base of the carb and affecting the operation of the choke?

Or a pinched vacuum line to the vacuum advance

Or a weak ignition coil

Or a broken or deteriorated wire from the coil to the distributor or a similar wire within the distributor

Or a bad or under lubricated bearing on the vacuum advance plate?

God, I was never any good at riddles...

I have thought long and hard about this one but all I can come up with is my normal location for a problem.....

For me it's always between the keyboard and chair....or in car parlance, between the boots and the tool.

We need a diagnosis so we can proceed with a cure. (we got more opinions at Charlotte on that hot parking lots at 11 pm --- maybe it was the beers...bud=wiser --->groan...)

It was running fine in Charlotte although the generator went south and had to replace it with at least 20 drinking knuckleheads watching in aforementioned hot parking lot.

It always ran hotter than my Special, so I had the radiator re-cored (recently). New water pump after a slow leak developed.

When I drove it to the St. Louis Regional it drove fine up there, but seemingly instantly, it wanted to die at stop lights, or on the highway when traffic slowed. I thought perhaps a piece of gunk had broken off from inside the fuel line (gas tank has been boiled...no rust). New sending unit. I tried turning out the carb screws and setting the idle faster, just to make it home from St. Louis.

Gotta remember to pull carb and readjust floats when I get back to Austin. This car drives great at 80 mph. Why do I have to stick it in neutral and goose it at traffic lights even though I messed with the idle?

Gotta be that stinking Carter, what do you think Old Tank? Do you agree? Can you look at it for me after you fix those Chihuahua horns....please?

Where is Jon when we need him??

Ben

Where is Jon when we need him??

Ben

Jon just saw the thread.

From what I read, "cruise" is good, but "idle" is not. Several possibilities come to mind:

(1) If the points have been replaced by a pertronics conversion and the generator was not replaced with an alternator, this is exactly what I would expect.

(2) A deteriorating vacuum hose somewhere, would cause a vacuum leak which would be significant at idle, but not an issue at cruise.

(3) Here in Missouri, the "corn squeezins" go bad after 30 days, which would cause these symptoms

(4) An increasing amount of deathanol in the fuel. On carbureted engines, we suggest checking the diameter of the idle tubes, and increasing the diameter of the idle tubes by 0.002 to compensate for the reduced energy in deathanol.

(5) The volatility of modern fuel causes evaporation of the fuel from the carburetor. On a vehicle which is driven infrequently, the smallest orifices (the idle tubes) can be partially plugged.

(6) And of course, the vacuum advance in the distributor could be non-functional.

Suggestions:

(A) Check all vacuum hoses. If possible, attach a vacuum gauge, and get a vacuum reading at idle.

( As a test, disconnect the inlet fuel line from the fuel pump and plug it. Now feed the fuel pump from a 5 gallon can of fresh gasoline. This test will tell you if the fuel in the tank is bad.

© If the points have been replaced by the pertronix, and the generator has not been replaced with an alternator, try reinstalling the points as a test.

(D) If A, B, and C above do not find the culprit, open the carb and check the idle tubes.

Please post your findings, the solving of an issue always helps the next individual to have a similar issue.

Jon.

It was running fine in Charlotte although the generator went south and had to replace it with at least 20 drinking knuckleheads watching in aforementioned hot parking lot.

Hey I resemble that remark!

When we talked in St Lewie, we suspected fuel issue, and it still makes most sense. Please do not put an Edelbrock on it, if you are going to lose that cool air cleaner, it might as well be to fuel injection. I think a WCFB is a rebuildable deal and like Carb King says, make the modifications for the sour mash in the gas. I have taken to regularly adding fuel system cleaners in the carbureted Buicks. It is funny how much more we pay for significantly lower quality fuel now than we used to pay for better stuff.

A few more observations: while the crossover was off for the pan removal it was noticed that the inside of the left side exhaust manifold was black vs gray on the inside of the right side; after it was all assembled it would not start...fire but would not run. I pulled the wire out of the coil and a big fat spark jumped out of the nose. I propped the choke and throttle plates open for a few hours and it finally started, but still ran badly. I tried an old trick that worked on a ford flathead: rev it up and just about when you have it wide open close the choke....no joy (the jets on the flathead are at the bottom of the bowl and often one would clog with sediment to the point of running on only one bank --- the increased vacuum would sometime dislodge the clog so I did not have to disassemble just to get home).

Willie

The different colors in the 2 sides of the exhaust manifold would suggest one side of the carburetor is partially plugged.

I would check the idle tubes.

Jon.

Mike, as you are aware, I had a tough time keeping my "56 running as well. If I remember correctly it took a couple of good carb cleanings to correct the issue.

From this post:

http://forums.aaca.org/f115/looking-advice-339572.html

Always be sure the ignition is functioning correctly. Then while the spark plugs are out do a compression check. With the sudden onset of the problem, ignition is most likely since fuel system problems are gradual and compression problems are isolated to one or two cylinders.

Willie

Somebody should listen to their own advice!!!

From this post:

http://forums.aaca.org/f115/looking-advice-339572.html

Always be sure the ignition is functioning correctly. Then while the spark plugs are out do a compression check. With the sudden onset of the problem, ignition is most likely since fuel system problems are gradual and compression problems are isolated to one or two cylinders.

Willie

Somebody should listen to their own advice!!!

Yeah, a little voice in my head kept sayin' that, but... I chose "I want to skip that step and try something else"...it's only been 5,000 miles!

Finally I got out the timing light and dwell meter.

The dwell should be around 30*, but was 50*:eek::eek:...the points were way too close and essentially not opening.

The timing is supposed to be around 5* BTDC (before top dead center), but was over 10* ATDC (after top dead center):eek::confused:.

After I got the distributor out, I found that the vacuum advance was shot, the breaker plate was worn, and the distributor shaft had nearly 1/8 inch of play at the top.

(I want it noted here and for ever after that this is the first time I touched that distributor)

Anyhow I pulled a better distributor out of my pile, installed a better breaker plate, new vacuum advance, new points (Standard BlueStreak), condenser. It started instantly and ran smoothly even barely ticking over while I set the timing. The timing ended up at 10* BTDC after the distributor was snugged down. It ran good except for some part throttle detonation --- backed off to 7* where I run all my 55's and now it runs perfectly!

Cheap-arsch points' rubbing block wore down after 5,000 miles along with a marginal distributor compounded by NDG vacuum advance.

...it's only been 5,000 miles!...we don't need to check that! It's got to be the carburetor this time!

Willie

So the moral of the story is that sometimes we trash perfectly good carburetors.

Bookmarked!

Willie, I just found this thread. Funny thing, my 55 264 WCD 2 bbl was doing exactly the same thing, all same symptoms. I counted turns to bottom and removed both idle screws, blew compressed air back thru screw holes with a pointy nozzle, ran screws to bottom and backed out. Ran perfectly again. Trash in idle circuit, wouldn't idle and stumbled badly. TexasJohn55

Willie, I just found this thread. Funny thing, my 55 264 WCD 2 bbl was doing exactly the same thing, all same symptoms. I counted turns to bottom and removed both idle screws, blew compressed air back thru screw holes with a pointy nozzle, ran screws to bottom and backed out. Ran perfectly again. Trash in idle circuit, wouldn't idle and stumbled badly. TexasJohn55

Hot dang is was the carburetor this time!

Can turn the idle screws with little or no effect .....

Worn throttle shafts and/or warped carb body/horn components upon torquing of screws with gasket in place.

So this Is a my guess Mr Willie....

I have a 1958 Buick that showed the same symptoms: running great over 1,000 rpm but would stall below.

I did the usual checks: timing, dwell, vacuum advance. Rebuild fuel pump with ethanol resistant kit, rebuilt carburetor with ethanol resistant kit. This fixed the problem until I re-filled the tank. I could barely make it out of the gas station. The fuel filter (old glass style with modern filter element) looked clean. So I opened the carburetor again and it was full of of some grey, grease-like gunk. I cleaned the carb back out and blew compressed air through the idle screw openings. It ran again for a while, then the same symptoms came back. I used my inspection camera to look inside the tank and found no rust, but some white "crust" in some places.

The 58 Buick used what they called a never rust fuel line: they simply ran a rubber hose from the tank to the fuel pump. Thinking that the ethanol is deteriorating my fuel line (that's at least what I read about ethanol enriched fuel), I replaced it (all 15 feet from tank to pump) with an ethanol resistant product. While working on the fuel line, I decided to replace the element in my glass bowl fuel filter (last filter change was performed by the previous owner). When I took the filter element off, I realized that there was an O-ring on the center post. This O-ring is necessary when you use the original ceramic filter insert with the aluminum back plate. With the modern filter element, it prevents the filter from fully seating, allowing the fuel to bypass the filter...duuuuh. So I removed the O-ring and just to be sure, I added another disposable fuel filter after the tank. Since then, I have no issues with my idle anymore.

Just my two cents,

Chris

I may have suggested this on another thread or on another forum, but this was a similar problem on another

old car. It was due to a previous owner sloshing that "gas tank sealer" stuff in the tank (remember those kits?) ..... probably before

ethanol was pervasive.... The clue is that the car ran flawlessly at first, then deteriorated quickly.

In this case the fellow was using ethanol & did in fact pull the tank down and found the grey/white sealer gunk coming off in chunks and

sloshing around in the tank. I believe he had to have it professionally opened up and stripped and

cleaned.

I wonder how many old cars that had their tanks "sealed" with those kits in the

80s and 90s and 2000's, are now having the coatings disintegrate with ethanol....?

mike

I was just working on a 55 with a Rochester that has been rebuilt twice relatively recently. I checked all of the ignition settings, changed what needed to be changed and there was still bogging.

When I opened up the top of the carburetor to check the float settings, I discovered that the accelerator pump cavity didn't have a check ball in it, the power piston was missing, and the choke was set up backwards as well as some slightly crusty jets.

It WAS the carb this time...

When I opened up the top of the carburetor to check the float settings, I discovered that the accelerator pump cavity didn't have a check ball in it, the power piston was missing, and the choke was set up backwards as well as some slightly crusty jets.

It WAS the carb this time...

I respectfully disagree Mike. I think it was the nut.

The nut that put the carb back together last time.

I have read through this thread looking for my answer. The problem: My '58 just died one day, no fuel. While replacing the fuel pump I also blew air back through the line to the tank and changed the fuel filter. Presto, we were up and running again. For a bit anyway. I noticed lots of fine black sediment building in the clear fuel filter and soon the car would run rough, hesitate on acceleration and finally just quit at stop lights. I changed the filter and this seemed to help a bit for another few outings but still the hesitation was there. It seemed to run out ok at cruising speed, but rough at low rpm. And now she just dies like she's out of fuel. Will re-start, run a bit, then die. Aargh.

So, this winter I'm planning to get the original carb re-built (it's long over due), change out the fuel line and get the fuel tank cleaned. Any notes on the procedure to drain, drop and clean the tank? Any tricks to getting the fuel hose changed out? I read here that it is all rubber from tank to pump? Is the fine black residue I'm seeing in the filter from the old fuel line as todays new fuels eat it away? Looking for tips, cautions and a bit of an overview. Thanks folks!

Hello Mit,

My 1958 Buick Super had the same symptoms: I rebuilt the carb and after only a few days of driving it would not idle anymore. When I opened the carb again, I saw greyish goo floating in the bowl again. To make a long story short, I found and did the following:

1. The original glass bowl fuel filter uses an O-ring in combination with the original aluminum backed ceramic filter element. The modern paper filter insert must not use the O-ring, otherwise fuel bypasses the filter as it will not seal.

2. I replaced the fuel line (which is original a rubber hose from tank to fuel pump to carburetor - back then advertised as a "non-rust fuel line") with a fuel hose that can handle all kinds of fuel, including high concentration of ethanol, not just pure gas. I found that the ethanol in the modern fuel dissolves the fuel line and produced the greyish goo. I found the fuel line at O'Reilly.

3. I rebuild the fuel pump with an ethanol resistant kit to avoid having the rubber membrane dissolved.

4. I rebuild the carb with an ethanol resistant kit for the same reason as #3.

5. Placed another see-through fuel filter in the line as the "suspenders to the belt".

Since performing all those tasks, the engine runs flawless without any problems. And even though I have two fuel filters now, they stay clean without any goo build up.

Christian

I just read the whole thing. That was quite a story.

Well, I guess I'll take my ethanol filled, biased tired, single piston master cylindered, copper radiatored old Buick up to the China Buffet at the other end of town for lunch. Tuesdays are my long day.

I'm gonna shake things up and mix them pretty good. Like Tina says "I don't do nuthin nice and easy, I like it nice,... and rough. Maybe that keeps me and the car going.

Bernie

Thanks Christian, I'll try all of the above. Did you do anything with your gas tank, or are you letting the filters take care of any issues that might be coming from the tank once you replaced the furl line rubber?

Bernie, you are a HOOT!! I sometimes have a hard time following your unique writing style but I always enjoy your posts!.........John

Hello Mit,

I had checked my tank with a endoscope camera and except for a few dime size rust spots on the top side I did not see much rust or dirt build-up. So at this point I let the fuel filters do the job.

You could try to just pull the fuel sending unit and check if the mesh sock is plugged up, too (but the it would not run at cruising speeds), but I don't know if you can pull it without removing the tank. To drop the tank, I would place a large enough piece of plywood on a shop jack, bring it up until it touches the tank, remove the nuts of the tank straps and lower it down.

Christian