I Must be doing something wrong

[buick5563]

Smithbrother, you are absolutely right. Modern cars are a whole lot better and reliable than they were years ago (for the most part) - especially ignition. Plugs last 100, 000 + miles, they dont even HAVE distributors. Things are now computer controlled and tiny engines are putting out more horsepower with better mileage than the monsters of years ago. No carbs to fool with or get messed up. Engines go forever.

One other very significant factor - all that electronic stuff is a whole lot cheaper to manufacture. (Not maintain if it should break)

Would I be willing to go back - no way! Every time I drive in pouring rain or cold or in incredible heat I think - "what would this have been like in my 1918 Buick?. Or even the 38's?"

Sorry for the highjack Brian. I must agree with Don. I love all of my old cars (some have Pertronix, some don't, in keeping topical)

I just drove my 55 Special home 60 miles after working on the Century wagon's rear main seal with Willie. Stuck twice in rush hour traffic and watching the temp gauge go up while my feet sweat from the exhaust heat looks great to the passers-by, but it is a white knuckle experience driving even "modern" old cars like my 55's. Plus, it's January and almost 80 degrees so not exactly summer weather.

Back to the discussion...

[38Buick 80C]

OK so tonight I put the distributor (and vacuum advance and points and everything but the rotor and cap) from my dad's 38-81F (which was running great) I took the car for the spin around the neighborhood and I think the stumbling issue is still there at WOT. I have to drive it around the research park tomorrow where I can get a bit more speed and there are more hills to put it under load to confirm it is still there.

So a note of interest. I definitely have a choke issue as the only way I can get the car to idle is with it disconnected.

So from here assuming the issue is still there when I test it again at lunch tomorrow, I am going to swap out the carb (the whole thing, choke, start switch) off dad's 38-81 (which is running right). If that doesn't work I'll be borrowing a known working coil (to make Mr. Earl happy) from one of Dad's cars. I've decided swapping out known working parts one at a time I'll be able to isolate where my issue is and then fix the issue accordingly.

The only caveat. I had to promise Dad I'll return anything off his cars. He says they are not parts cars.

[buick5563]

Dude...all cars are parts cars if they are running right!

[BUICK RACER]

This is a serious thread, makes me want a '38 Buick even more!

[smithbrother]

You have ONE SMART DAD, LOL.

Dale in Indy

[Marty Roth]

Brian,

You are taking a good approach, being careful to swap out components from a known good source, and to do them one at a time.

I wish you success in your quest to be able to drive a great car the way it was meant to be driven.

As the ad said, "When better cars are built.........."

[60FlatTop]

Brian,

When I read your last entry I got curious about your float. In some rare cases the solder has deteriorated and allowed fuel to leak inside to make them just a little heavy, the way Q-jet composition floats sink. You can test by submerging your float in a pan of hot water and watching for fuel bubble vapor bubble out.

When the bubbling stops your can wipe the area with fresh solder and fill a pinhole.

Bernie

[DonMicheletti]

Brian,

One thing you might try that is very easy is do as one of the other posters mentioned. Take the little cable between the choke mechanism and the butterfly shaft out. The butterfly will then open fully. Maybe do that after the engine is warmed up. If removing the cable helps and the car runs OK - you have your answer.

That is a lot easier than swapping carbs.

If the cable thing doesnt solve the problem- them move on to the carb swap.

[38Buick 80C]

Ok went out for a spin with the choke disconnected and known working distributor. The same stumbling under load going up a hill or under load happens. So I'm going to eliminate the distributor as the issue. Leaving carb, coil, cap/wires, plugs, fuel pumps, fuel or some misc electrical issue.

Don I've taken the carb on and off so many time recently I've got to where it is a very quick interchange. Dad's gonna get me the carb on Saturday so we'll know more then.

[avgwarhawk]

Ok went out for a spin with the choke disconnected and known working distributor. The same stumbling under load going up a hill or under load happens. So I'm going to eliminate the distributor as the issue. Leaving carb, coil, cap/wires, plugs, fuel pumps, fuel or some misc electrical issue.

Don I've taken the carb on and off so many time recently I've got to where it is a very quick interchange. Dad's gonna get me the carb on Saturday so we'll know more then.

Typically, under load (under load usually entails going up hill, dropping into passing gear, etc.) stumble and bucking, etc. is usually a bad spark plug wire. This is my experience from years of trouble shooting driveability issues when I was turning wrenches.

Electrically, something is providing resistance.

Edited January 30, 2013 by avgwarhawk (see edit history)

[pirate]

I have to agree with Pete Phillips. I see no advantage to these electronic ignition conversions. Point systems are very reliable and yes, It can be almost always repaired to get one out of a jamb without the need for new parts. When electronics quit your almost always dead in the water. The theory that one gets a hotter spark makes no sense. All the electronic in the distributor does is make and break the 6/12 volts. The coil determines the high voltage of the spark. I suggest you keep the points in the distributor and send back the electronics

[avgwarhawk]

I have to agree with Pete Phillips. I see no advantage to these electronic ignition conversions. Point systems are very reliable and yes, It can be almost always repaired to get one out of a jamb without the need for new parts. When electronics quit your almost always dead in the water. The theory that one gets a hotter spark makes no sense. All the electronic in the distributor does is make and break the 6/12 volts. The coil determines the high voltage of the spark. I suggest you keep the points in the distributor and send back the electronics

I believe he has. The issue of hesitation under load remains.

[Joseph P. Indusi]

I have a few of these rotors with the resistor. I do not like the way they put these together. I assume these were to supress ignition noise for the radio. I have a Pertronix on a 53 Special straight eight and never had any trouble with it. I use the regular straight rotor but have installed resistor spark plugs and stranded copper ignition wires. I do not get any noise in the radio.

My 2 cents.

Joe, BCA 33493

[Ben Bruce aka First Born]

I have installed a Pertronix in my '50. I used the original rotor, I believe. Very satisfied.

Ben

[buick5563]

Just another thought. Is the stumbling an actual gas (ethanol) issue?

[carbking]

Since the pertronix problem seems to have disappeared along with the pertronix, trying to address the current overrich condition:

Are you still running either the original Marvel or Stromberg 1938 carburetor with the "didn't work when new" Delco choke?

Stromberg tried to convince Buick to use the Stromberg choke, but since Delco was a GM affiliate, Buick refused. The 1938 Buick carbs (as well as the 1939 carbs) were basically experimental carbs. The Delco choke units simply did not work (unless you lived in a climate such as San Diego or Miami). Somewhere, I have a factory bulletin which advocates absolute butchery to the Delco unit, and even that does make the thing work well.

Fast forward to 1939. Buick finally dumped Marvel, and added Carter as their second carburetor supplier. At Buick's request, both Carter and Stromberg offered versions of the 1939 carburetors (with conventional hot air integral chokes) with the necessary throttle linkage modifications to work on the 1937 and 1938 Buicks. THESE WERE ASSIGNED BUICK PART NUMBERS AND SOLD THROUGH BUICK DEALERS! Probably 90 percent of the original 1937 and 1938 carbs were trashcanned at this time by people who really wanted to drive their Buicks.

I understand wishing to keep things totally original, and applaud anyone trying to do this. However, for a car that is driven, sometimes it is a good idea to look at the history of factory modifications.

The Delco choke didn't work; and unlike a fine wine, age has not improved its performance.

As far as the pertronix is concerned, I agree completely with Pete. The two most common "carburetor" issues we see today are having to tune for the ethanol, and getting the car owner to try reinstalling points and condensor. To be perfectly fair to pertronix, we see far fewer percentage-wise problems with pertronics if the generator is replaced with an alternator. The alternator keeps a more stable voltage, and electronics prefer stable voltage.

If you live in a climate where you can start your Buick without a choke; try disconnecting the choke, and using one of the plastic ties to tie the choke butterfly in the vertical (wide open) position. See if that helps the issues you are currently experiencing once the engine is at operating temperature. If the issues disappear, you will have found the source of the problem. Then you can decide to keep the issues, or do what 90 percent of Buick drivers did in 1939!

Jon.

Edited January 31, 2013 by carbking (see edit history)

[avgwarhawk]

The only experience with a choke issue I have had concerned a variable venturi on my 80 Lincoln. The choke would produce a bucking and hesitation. Only until fully open and hot did the 351 run as designed. However, variable venturi carbs are in short...garbage.

I'm still of the mind that the issue is electrical.

[DonMicheletti]

Carbking, I like your comments on the choke mechanism. It probably could be called a Rube Goldberg. I dont think they could designed a device that was more complicated and ineffective. I live near San Francisco so I can live with less than a perfect operation - I just go for open butterfly at operating temp and marginal choking when cold.

Brian,

I'm really anxious to see what the final and successful solution will be - you'll get there.

I have another idea and maybe Carbking can comment.

I think you have said that the carb was rebuilt. If, by some chance, the main discharge jet (#3 in the manual) was installed with the top angle wrong, could that be this problem?

Don

[carbking]

Copied from the original posters info in post #23:

"I suspect the answer lies either in the distributor or the carb. With the carb rebuilt and the issue still occurring I figured distributor hence the pertronix to "simply" things. Vacuum advance works well test several different ways and with a vacuum pump at different points in the line. I had the distributor rebuilt during the restoration and I may have to borrow one off my dad's 38 RM just to eliminate mine as a suspect as they say on all those crime shows. I'm kind back to the carb as the potential source of the issue and here is why. Upon start up tonight going back to point the exhaust is coming out very black and the car was idling a bit rough. I goofed around some after the car warmed up some and found if I held open the butterfly at the top of the carb it ran much better. So I'm thinking more air compensates for too much fuel and fuel mixture gets better so car runs better. The other thing that is happening just goofing in the garage is I can make the car back fire through the carb or stumble with a quick pull of the throttle rod (like putting the petal to the floor). "

This post is the reason I posted post number 56 above. The Delco choke will NOT move the necessary distance to go from closed (if correctly set) to wide open (the proper position once the engine is at normal operating temperature). If the choke plate is not in the vertical (wide open) position when the engine is warm; all kinds of symptoms are possible.

There may still be electrical issues, but these will be impossible to properly diagnose if the choke butterfly is not open.

And Don, even Mr. Goldberg would never have claimed the Delco choke!!!

Jon.

Edited January 31, 2013 by carbking (see edit history)

[avgwarhawk]

The other thing that is happening just goofing in the garage is I can make the car back fire through the carb or stumble with a quick pull of the throttle rod (like putting the petal to the floor).

This was quoted in another post (your entire entry but lets focus on this).

Back fire through carb causes:

Fuel pressure drop

Timing

Spark plug wires installed in wrong order

Vacuum leak

Problem with ignition system

Leaking intake or exhaust valve.

[carbking]

The only experience with a choke issue I have had concerned a variable venturi on my 80 Lincoln. The choke would produce a bucking and hesitation. Only until fully open and hot did the 351 run as designed. However, variable venturi carbs are in short...garbage.

I'm still of the mind that the issue is electrical.

Actually, the variable venturi carb was a good design. It did have major problems because of.................ethanol! The carb was so designed that fuel would sit on one of the diaphragms. With gasoline, no problem. With ethanol......failure. So the fact it is almost impossible to keep the carb functional has the carb as the culprit. While I am not a big fan of some of the emissions designs of the late '70's and '80's, I do believe it is only fair to throw rocks in the proper direction.

Jon.

[avgwarhawk]

Actually, the variable venturi carb was a good design. It did have major problems because of.................ethanol! The carb was so designed that fuel would sit on one of the diaphragms. With gasoline, no problem. With ethanol......failure. So the fact it is almost impossible to keep the carb functional has the carb as the culprit. While I am not a big fan of some of the emissions designs of the late '70's and '80's, I do believe it is only fair to throw rocks in the proper direction.

Jon.

I have not hear of ethanol being a issue for the Motorcraft VV. The VV is a unpleasent carb no matter what one is doing to it. Ethanol. Cold Enrichment problems. Choke issues. Working on it was a nightmare. Early emissions devices that were truly untested. TPS and ECM that created more issues than solved. Direct replacement suggested.

[FLYER15015]

Brian,

Just to keep this wandering discussion on track, and after reading all the posts, I'm in Marty's camp mostly.

Were it me......... I would first double check my float level, make sure the mixture jet holes are clear and the needles are 1 1/2 from the bottom, then add a manual choke, and ditch all the pertronics stuff.

Just my $ .02....and worth every penny.......

[60FlatTop]

I see float level pop up again. Here is some general information to store away.

I own a 2005 Chevy Silverado 5.3 Flex fuel truck. When it was new I bought the 5 volume factory shop manual set. Although I didn't read every page I have turned most and looked at the pictures; read what caught my eye.

The flex fuel system has a small referencing tank ahead of the fuel tank. It contains a float that measures the specific gravity of the fuel much the way an anti-freeze tester works. The float slides on a resistance element that feeds a voltage signal to the ECM telling in how to tune the engine for fuel of varying densities (Sp. Gr.). A float is a float.

I tried using the corn liqueur in my truck for about 3,000 miles around 2010. Mileage varied a lot by tank full, performance was degraded, and I got vent system code CEL's. Variations in fuel quality may have been unpredicted by the 2005 flashed program or the fuel standard is not maintained. The stuff didn't work well with a car designed for it. AND the operation was based on a float sensor. A float is a float.

Bernie

[38Buick 80C]

Dad brought the carb over, but one of the comments above mentioned plugs, so I replaced all the plugs. Still the same issue.

So current state

1. Know working distributor (with all the points etc) swapped out and still installed

2. Plugs swapped out for new (AC-46) and still in

4. choke disconnected after warm up.

Next step

1. swap out carb and choke as a unit with known working carb and choke unit

2. test

3. if still an issue, on to a known coil.

4. test

5. if still an issue known working cap rotor and wires.

6. test

[60FlatTop]

Brian,

When you've gone over and over the system maybe one of these places is near you: Ethanol-free gas stations in the U.S. and Canada

Just a little test, you know.

Bernie

[38Buick 80C]

OK it's not the carb. Though at first I thought it was running better but then it got back to usual. So the more it runs the worse it gets. To the point where I can only barely keep it driving (idle is ok but not great) after 10 min of running. Of note to get the car home from my test drive I actually had to drive it home in reverse the last mile or so (that was fun), I point it out cause I could actually keep it running better (not great still would stall out after frequently) in reverse than in forward gears if that makes any sense at all. Got some strange looks driving a '38 Buick with no roof backwards down the public 4 lane rd. luckily Sunday morning there was no traffic. :-)

On to the coil, wires and Fuel

[DonMicheletti]

Brian,

Boy, I dont envy you.

I doubt that the ignition would know that the car was running backward.

Do you have an electric fuel pump on the car for priming the carb? If so, have you turned it on when you experienced the running problem?

Don

[carbking]

Is the choke butterfly in the vertical (wide open) position?

Jon.

[38Buick 80C]

Yes I do have an electric pump and I do use it for priming and have tried to use it when the issue occurs and it does not seem to make any difference. The thought had occurred to me that maybe the fuel is vaporizing in the line where it is routed past the front of the head, but the electric pump should alleviate that I would think.

Jon,

When the engine is hot but not running the choke is not totally open, but close (with the borrowed carb/choke unit installed, the old unit is another matter). When it is hot and running yes it goes to wide open.

[60FlatTop]

I sure wish you liked closer we would have had it fixed. When I used to get cars in I would pressurize the cooling system hot and cold, do a compression check first, take off the valve cover and match valve action to rotor location, ohm the plug wires, ohm the primary circuit with no power, scratch 'n sniff the fuel, look for squirrels in the air cleaner, and all kinds of weird stuff. I have about 8 days before our next contract starts. Send 'er up.

That backing up thing makes me suspicious of the power valve.

Bernie

[38Buick 80C]

Well its not the coil. Nor is it the gas cap not venting.

I checked all the plug gaps again and the points gap and retimed it.

New plugs are fouled already. How do I get a leaner mixture at full throttle /load?

Gonna reset the valve lash for good measure too as it does get worse when hot, but I think it's just getting more and more flooded.

[DonMicheletti]

Brian,

One of the things that puzzles me is that you seem to have the same "run rich" condition in spite of the fact that you have used a second carburator that was OK on another car (is thst right?).

I'm really anxious to see what the problem might be.

[old-tank]

plugged muffler?

heat riser stuck closed leading to percolation from carb?

[john hanson]

Brian I think i have the same system in My 38 Buick and was hard and slow starting . that was right after i rebuilt it with new battery . one day i just bought a new battery again. Dont ask me why i just did. Has started every time since like it should. so what i am saying is I think the boys are right. What you have low voltage . I don't know if you can but try and set up another battery and run power off that to coil only and use your regular battery to crank with.

John Hanson

[jackofalltrades70]

Brian,

I thought I would chime in as this hasn't been brought up. What type of plug wires are you using? If you are using hei type plug wires, this could cause all of the previously stated problems.

Most wire sets you will purchase today are the newer HEI (High Energy Ignition) type. These wires are designed for use on ignition systems with outputs of 35,000 to 45,000 volts. Your original classic point-type ignition system operates in the 20,000 volt range. Putting modern HEI wires on your 20,000 volt classic ignition system causes low voltage to the spark plugs, resulting in hard starting, poor gas mileage, decreased performance, rough running, fouled plugs, and other symptoms that seem carburetor-related, when, in fact, they are being caused by incorrect plug wires.

Just a thought. Matt

[Dandy Dave]

Brian,

I thought I would chime in as this hasn't been brought up. What type of plug wires are you using? If you are using hei type plug wires, this could cause all of the previously stated problems.

Most wire sets you will purchase today are the newer HEI (High Energy Ignition) type. These wires are designed for use on ignition systems with outputs of 35,000 to 45,000 volts. Your original classic point-type ignition system operates in the 20,000 volt range. Putting modern HEI wires on your 20,000 volt classic ignition system causes low voltage to the spark plugs, resulting in hard starting, poor gas mileage, decreased performance, rough running, fouled plugs, and other symptoms that seem carburetor-related, when, in fact, they are being caused by incorrect plug wires.

Just a thought. Matt

Totally Agree. I am amazed at the amount of people that do not relize that this is a real problem on anything vintage that has points ignition. Modern carbon wires just do not work. Thinking about it, even new lawn mowers and small engines still use solid core metalic wire. Dandy Dave!

[old-tank]

Brian,

I thought I would chime in as this hasn't been brought up. What type of plug wires are you using? If you are using hei type plug wires, this could cause all of the previously stated problems.

Most wire sets you will purchase today are the newer HEI (High Energy Ignition) type. These wires are designed for use on ignition systems with outputs of 35,000 to 45,000 volts. Your original classic point-type ignition system operates in the 20,000 volt range. Putting modern HEI wires on your 20,000 volt classic ignition system causes low voltage to the spark plugs, resulting in hard starting, poor gas mileage, decreased performance, rough running, fouled plugs, and other symptoms that seem carburetor-related, when, in fact, they are being caused by incorrect plug wires.

Just a thought. Matt

Totally Agree. I am amazed at the amount of people that do not relize that this is a real problem on anything vintage that has points ignition. Modern carbon wires just do not work. Thinking about it, even new lawn mowers and small engines still use solid core metalic wire. Dandy Dave!

Count me as one more in agreement. Another issue is spark plugs. Try to find standard and preferably non-resistor plugs --- never platinum or other high mileage plugs. I once tried some Bosch platinum plugs in a nailhead and it was very hard starting and had driveability issues. Pulled a plug and it would not start a lawn mower. Checked for spark and there was a tiny yellow spark...substitued a new Autolite 75 and (splat-splat) big blue spark. Installed same in the nailhead and it starts first piston up.

Willie

[38Buick 80C]

Well the plugs' are AC46's the correct plugs from the factory for the car no resistance or anything. The wires are from Bob's and as far I know they are nothing special, but I have another set off another car known to be working that I can try.

Willie. I checked the the heat riser thing and it moves freely. will have to check that it is open when hot.

[DonMicheletti]

Brian,

Seems like you have done everything so far and still seem to have a rich running condition. I know it is a long shot - but do you have a newly rebuilt fuel pump on the car? If so there might be a remote possibility that it has the wrong spring in it and you have to much fuel pressure to the carb. Can you check that? it is a long shot,

I just went through a fuel pump fiasco with my Roadmaster where it turns out that the pump on it is not correct and was built up from several different pumps. That pump was on the car when i bought it 27 years ago and had been working fine. I was nervous about the fuel with ethanol and decided to rebuild the pump myself. That is when I found the situation. Bill at Bobs Automobilia was great and helped me a lot to gather all the parts to get the pump rebuilt. He did a great job of identifying the differences. As is turns out, my pump body was for a 55 V-8 spliced together with '38 parts too. The pump is fine now.