Help me fix my 1949 Cadillac

[manncad]

Hi, I'm a french winemaker who worked 8 years in Napa CA.

Back in 1999, I bought a 1949 Cadillac, I restored it myself after getting lots of information from the right people at the right time. Now, it's back in France. It always ran very well until a few months ago when it started to smell gas, smoke black and also the ignition coil would get really hot. So I changed Distributor cap, rotor, condenser, plugs, wires plugs, points, gaz pump, and ignition coil...nothing changed. I am out of ideas. I took apart the carburator but everything looked ok.

I'm ready for any suggestion.

Thanks

Emmanuel

[mrpushbutton]

Do you have good compression in all 8 cylinders?

[RocketDude]

Black smoke, you have an over rich condition. Your carb is flooding or the choke is stuck. The gas smell confirms it. Keep looking towards the carb, maybe the choke isn't opening as the engine warms. wire the choke open and see if that makes a difference.

[manncad]

I think the compression is good but how can I check it ?

I am not a mechanic, more like a winemaker, but I learned a lot in the US. Here in France, we don't have big V8 and everything is now electronic, so it's hard to find a real good mechanic.

Is the choke the " trapp " on top of the carburator ?

[Dave@Moon]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Is the choke the " trapp " on top of the carburator ? </div></div>

Yes, although it's more commonly called the "butterfly". It closes off the air intake to the carb to create a richer mixture for cold conditions at startup.

One question: Does the black smoke occur all the time or only when you first start the car? My Buick did all of the things you describe when gasoline was reformulated in the U.S. to boil at a lower temperature in the late 1990s, except that the black smoke (very intense) only occurred for the first 30 seconds or so of driving. The heat from the engine at shut-off was boiling the gas in the (very small) carb, where is would either drip out the sides of the carb or down the carb throat. The gasoline odor was naturally overpowering. This created itensely rich conditions for a few minutes the next time it was run, until the car ran for a while and cleared it out. It was bad enough to foul plugs in 300-500 miles despite getting 13-17 mpg and running like a new car.

If your carburetor settings and functions are all O.K., this may be your problem. I was only able to correct it with an electric fuel pump and by relocating the fuel line away from the motor.

[manncad]

yes, the black smoke is mainly when I start and for about 10 mins when the car is warming up. I actually looked at the plugs and they are really black. I just received new ones but I know if I put the new ones in, they will be black too. What pisses me off is that this car always ran well since 1999, and I probably did something wrong one time and now, I can't adjust it. I need to readjust the butterfly then. The gas odor is terrible though, very strong. I also realized that the gas mileage was very low since that problem occured.

This car has been running in France since 2002 on unleaded gas without problems.

So, what should I do exactly ?

[manncad]

I actually forgot to say that the main problem is that when I accelerate, it's missing, like if the car had no power anymore. 1st and 2nd gear ok, and then when it's on 3rd and 4th, it doesnt run well.

[Guest imported_JPIndusi]

It is hard to diagnose a problem from a distance, but I also keep thinking about the carburetor. I suspect that the float or the needle valve are not functioning properly inside the carburetor. Sometimes there could be dirt or a particle lodged between the needle and seat or the float is porous and is not at the correct level. You must remove the carburetor and check all of these possiblities.

Good Luck.

Joe, BCA 33493

[manncad]

when you say Needle, do you mean the 2 metering rods ?

I checked all this and it seems ok, but I will take it apart again and show it to a mechanic.

Thansks

[Guest imported_JPIndusi]

No. Needle and seat refers to the two parts that make up the valve that lets fuel into the carburetor bowl. When closed, that is no fuel coming in, the needle fits into the seat and does not permit fuel to enter. The float tang or arm is connected to the needle. When the fuel in the carburetor drops, the needle moves away from the seat allowing fuel to flow from the fuel pump supply line. If thre is dirt on the space between the needle and seat it will stop the needle from closing off the fuel supply. If the float is porous it will sink and allow the needle to open and let in more fuel than is needed, leading to fuel smell and rich mixture.

Joe, BCA 33493

[manncad]

thanks for all your help but I did it all and it still doesnt run great. I don't get it. It starts perfectly fine, at idle, it's also perfect, and as soon as I accelerate, it's missing, it's not right.

I don't know what to do and I can't use this beautiful car. Too bad as it is finally sunny in France...

Any other suggestion would be great.

Thanks again.

Emmanuel

[Matt Harwood]

If the carburetor is in good condition and in tune, and you've checked all the other items above, perhaps double-checking the ignition system could be next? Black smoke indicates a rich mixture, but it may also indicate poor combustion. I noticed that you say your coil gets hot--do you have a spare you could use to check to see if that's the problem because there's no easy way to test a coil. They often work fine at low speeds, but under high demand situations, they start to break down and don't deliver full voltage.

Also double check the points and condenser, and make sure the timing is correct--too much retard could cause the smoke you describe and wouldn't be very noticable at idle. Since it only has problems under load and it misses badly, I'd check ignition next. It has to be fuel or ignition, and you've checked fuel.

Hope this helps.

[Guest BJM]

Every poster has mentioned the choke. Black smoke is a rich mixture. The reason it performs poorly in high gear range is the load is too much for the engine. In lower gears, the higher rpms are moving more air through the engine - enough to at least keep it running. When the shift is made to a high gear, engine rpms go down, meaning less air movement through the engine and a mixture so rich, that the motor is misfiring.

There is no need to keep wondering what it is. Your options are: replace the carberator with a reman unit from a seller you trust (might take some back and forth with the States) or try installing a manual choke to override the automatic choke, which should be bi-metal.

I had a similar issue with many of my US cars, two in particular I never could get the parts I needed for the automatic choke so I installed a cable operated manual choke.

Manual chokes in my opinion - are superior to automatic chokes but in the interest of progress, most manufacturers went to automatic chokes.

On manual chokes, typically the choke is 'slammed' closed to start then pulled out almost immediately about half way, unless it's really cold out.

Then if the black smoke still keeps coming, you know it's an internal issue with the carberator, as your choke "butterfly" should be straight up and down - if you still get black smoke then, then I wouldn't mess around with it - send it to "The Carberator Shop" with a list of symptoms and he will rebuild it perfectly and send it to you.

Or get a remanufactured one. But this thread has seen a lot of "paralysis by analysis" but everyone seems to agree on the same 2-3 issues. So get on it and do it, then advise us.

[Dave@Moon]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> thanks for all your help but I did it all and it still doesnt run great.</div></div>

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Black smoke indicates a rich mixture, but it may also indicate poor combustion. I noticed that you say your coil gets hot </div></div>

Matt is absolutely right about poor combustion, and all of us have been analysing this problem from the perspective of poor air flow and/or excess fuel to the cylinder creating a rich mixture and thus black smoke. There is another way that poor combustion can be created in the cylinder that'll result in excess heat and poor combustion.

If indeed you have eliminated the carburetor as the source of the problem, and you're getting good spark, you may want to check your exhaust system. A blocked exhaust can easily cause these symptoms. Perhaps the manifold gasket is incorrect or incorrectly installed, partially blocking flow. It's unlikely, but there also could be a foreign object blocking flow inside the pipe or muffler.

If <span style="text-decoration: underline">only</span> the coil is getting hot it's probably true that Matt's correct and it should be replaced. You <span style="font-style: italic">should</span> have a weak spark if that's the case. If the coil is getting hot and the area around it is as well, you may have locallized a blockage in the exhaust system.

I'd replace the coil first (after checking the other ignition components of course), they're not very expensive. If that does it, you're home free.

[manncad]

I'm so lucky to be on this forum. Thanks for all the infos again, you guys are real pros.

What you have to know is that the coil has always been an issue for me. I've changed it 4 times and the last one comes from the US, 3 weeks ago, and it still gets really hot. When I say hot, it's actually burning, you can't touch it. That's one problem. But even when it got hot, the car would run ok. I actually installed a second one for a while and when it would get too hot, I would switch coil.

Now, the black smoke is mainly at the beginning, then after 5 mins, it's not black anymore, but it smells gas all over.

I also changed the points, the rotor, the condenser, the cap. Maybe the points are not adjusted correctly. And I touched at the advance too, still waiting for a timing light to adjust the all thing.Maybe that's the problem.

Finally, the choke might also be the problem, even if it looks like it's working fine, I need to see a professional about that.

Last infos, a friend of mine in CA is working on finding another carburator for me.

Thanks

You all deserve a nice glass of wine.

Emmanuel

[Guest imported_JPIndusi]

It is rare to hear of an ignition coil that runs that hot. One cause might be a leaky condenser that still allows the car to run but draws excessive current through the coil. This might also explain the miss in the engine in the higher gears you describe. See if someone can check the condenser for leakage or replace with a known good one.

Any chance this car was converted to 12 volt battery system?

Joe, BCA 33493

[manncad]

yes, it is rare, but last owner, who is also my best friend in CA, keeps telling me it always been like that. Yes, this car was converted to a 12 V battery system.

Also, the condenser is brand new. It used to be one on top of the coil which I don't use anymore as a mechanic told me there was already one inside the distributor, near the points. I don't know what to do anymore, I checked everything. One last chance with another mechanic next week who told me it could be the choke...

I wish I would be in the US, my car would already be running for sure.

Back in 2000, I took all the wiring out and replaced it one wire at the time. I wonder if I did something wrong with the wiring going to the coil.

Anyway, thanks again for your infos, I'll keep you posted.

Emmanuel

[Guest imported_49packard]

Stupid question-you do have a 12v coil in it-if it has been converted to 12v?

[Dave@Moon]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Also, the condenser is brand new. It used to be one on top of the coil which I don't use anymore as a mechanic told me there was already one inside the distributor, near the points. </div></div>

The condenser mounted on the coil was almsot certainly there for AM radio interference suppression. Ignition condensers are almost always mounted inside the distributor, as you state.

If you disconnected/removed the radio suppression condenser it shouldn't have effected anything except AM radio reception, <span style="font-style: italic">unless</span> some of the other wiring was mounted to the original suppression condenser points instead of the correct location.

Maybe if you can post a photo of the coil someone could spot a problem?

[RocketDude]

If it has been converted to 12V, I have to ask, do you have a ballast resistor in the circuit to cut down the voltage to the coil? 12V coils are not designed to run on 12V's. The resistor cuts the voltage down to about 8V..! If you don't have the resistor, the coil will absolutely get hot..!

[Guest imported_49packard]

I would expect the car still has the 6v coil with 12v on it. A coil is a transformer-which consists of coils of wire wrapped around a steel core.

[Guest imported_JPIndusi]

RocketDude:

Exactly why I asked if this car was converted to 12 volts! If he doesn't have a ballast resistor he is cooking the coil and burning the points.

I hope we find out what is going on here.

Joe, BCA 33493

[manncad]

well, the coil is a 12 v and the wire comes straight on it. There is no ballast resistor. The only ballast resistor that I use is for the cigar lighter and the gas gauge ( the gauge stoppped working anyway, but that's not an issue ). So I have to try wiring the coil via the ballast resistor and see if it stops getting hot.

Thanks everyone

I'm supposed to take the car to a professional mechanic tuesday. I'll keep you updated.

Emmanuel

[RocketDude]

I don't know what kind of resistor you are using on your lighter/gauges, but go to any parts store and buy a ballast resistor for the specific purpose of reducing the voltage to the coil in a 12V system.

They were used for years before they were replaced with calibrated resistance wire feeding the coil. They should be available even in France, if not, always mail order.... Cheap, too..!

Change your points while your at it, they are probably toasted. None of that stuff likes full 12V's..!

Good luck.... Let us know

[Guest imported_49packard]

As I think I understand the situation. You have a coil that is designed for 6v operation being used on 12v. That increases the voltage to the plugs about 2x. Which will kill the plugs. Which is probably the reason for black smoke??

[manncad]

The coil is designed for 12 v operation being used on 12 v battery. The mechanic said this morning he didn't have this ballast resistor and that there was no point to have it anyway. The car stayed in the shop and he'll have a look at it. God I wish I had one of you guys right here right now to fix this all thing. But I'm not desesparate and I'll find the problem.

I'll update soon

[RocketDude]

If you have a 12V system and do not have a ballast resistor to cut the voltage down to 8.4 volts, you will ruin the ignition system. Perhaps French cars don't operate that way, but American cars most definately do. Your mechanic is completely wrong if he tells you a resistor isn't neccessary.

Here is a quote from a motor manual "the idea of the resistor is that you deliberately design

> the coil to operate at a voltage lower than 12 V and then use

> the resistor to get to that voltage under normal conditions.

> When you're cranking the engine with the starter the battery

> voltage drops and hence the sparks get weaker. To combat this

> you bypass the resistor as long as the starter is operating.

> This gives you pretty much similar sparks during cranking and

> normal operation.

Here is a page I googled..

http://aolsearch.aol.com/aol/search?encq...llover&ie=UTF-8

[RocketDude]

To further explain how that system works, the solenoid mounted on the starter will have two small terminals. One of them received voltage from the ignition switch which activates the starter when the key is in crank position. The second terminal is called the "hot Shot" terminal. Under cranking conditions only, that terminal will be hot with 12V's. A wire runs from that terminal to the coil, so you have 12V's during cranking, to give your coil the extra voltage for cranking. When the engine fires and you release the key, that wire is now at 0 volts, and your ignition system is now running on the 8 V's supplied by the ballast resisted wire. The hot shot wire bypasses the ballast resistor during cranking only, to give you a little extra POP for starting..!

I'm betting if you look at your solenoid, you will only see the one wire. The hot shot isn't hooked up because you are running on 12V's all the time. Put the resistor in the system, hook up the hot shot wire and then you can spend more time with the berries.....

keep the faith, this issue will be resolved

[manncad]

The car went to a first shop then a second one where I thought the machanic would be better. He adjusted the points, the advance and the 2 screws in front of the carburator. He told me the car was then running great, but without the air filter, which is plugged. So I went to pick up the car and realised it was not running well at all, even worse than before. Still black smoke, still missing and most of all, the coil burning hot. So I left without paying anything so far, a little pissed off. Anyway, I need to find a new and clean airfilter and a resistor ballast. So I have one question, can someone tell me what kind of resistor ballast I need for that car and where ? I will order it right away. I went online to look for it and there are a lot of different resistor.

Thanks

[RocketDude]

I listed a site in a previous post, as to where to get the resistor. Perhaps French vehicles don't use them, but they were common for so many years in this country, that just about any parts store will carry them, They should only cost 5 or 6 bucks.

If you still have a friend in the states, have him pick one up and send it to you. Or any mail order catalog.

I am going to a parts store this afternoon, I will see if I can pick one up for you. I will check price and availability and if you like what you hear, I'll ship you one.

If only I were a wine drinker, I have struck the mother lode...!

I'll get back to you....

[RocketDude]

If your old air filter has a number and brand name on it, let me know, I'll check on that too. I assume the stock '49 Cad had an oil bath, so if it has a paper filter, it isn't stock. with a number, I can cross it over....

[RocketDude]

I went to AutoZone and they have them is stock. $4.99 plus tax.... Here is a picture.

http://www.autozone.com/Ntt,Ballast%20resistor/shopping/allResults.htm;jsessionid=8A63771994692728AEEDF37CA3E18ED4

They can't weight more than an once or two, so shouldn't cost must to ship........

[manncad]

that would be so awsome if you get me this ballast resistor.

The old air filter has no number or name. They just call it Air Cleaner Filter Unit. Its quite big, with oil bath. I can't take it apart to clean the filter itself, and I dont think its papaer, it's most like a bunch of small wires. I don't know how to explain. if you give me an email, I can send you a picture.

if you ever find a resistor and a filter and ship it to me, don't worry for the payment back, my friend will send you a check from california.

As the mechanic worked on the car quite a long time, they want me to come back when I have the resistor and the filter to readjust the all thing, and then pay them, which is normal.

You know, I do believe the problem is the coil, it was so hot after 15 min drive, unreal.

[MCHinson]

It sounds like you have an oil bath air filter. Here is a link that includes a description and cleaning instructions for a similar one (although this one is specific to a VW).

http://autorepair.about.com/cs/doityourself/l/aa081603d.htm

[manncad]

yes, this is an oil bath air filter, I did change the oil but there is also a filter itself and it was very durty. This filter can't be taken off the unit, it's inside. The only way to clean the filter is to let it sit several hours in gasoline and then dry it off with compressed air. I did all this, it looked pretty clean but the car runs better without the filter on.

[RocketDude]

Send me your shipping address, I'll ship you a resistor. I just looked up one for a late 50's Cad. When they went to 12V, the resistor was used from that time until, I guess sometime in the 70's when they replaced the resistor with a special wire with the resistance build in.

BUNNELLYL@AOL.COM

This may not be the answer to all of your preformance problems, but it is a good place to start. Then you know at least that part is correct.

[manncad]

here is an update,

I got a resistor from RocketDude and put it on this morning....but....the coil is still getting really hot. And also, after cleaning really good the oil bath air filter, I put it on, and the car was missing a lot. So, I took it off and the car was doing much better, still missing at high speed, but more like if I was pushing the brake pedal every 3 seconds or so. And then, as I said, when I came back home after 15 mins drive, the coil was hot.

I mounted it on the fire wall, with the wire of the ignition and the wire of the fuel pump on one side, the wire going to the + of the coil on the other side. So maybe I should try another coil, maybe it got too hot before, but I doubt it.

The car is still smelling gas and still black smoke.

I'm back at the beginning, not knowing what to do.

Maybe it's a ground that need to be wired somewhere.....I have no idea. What's sure is that the filter is not good.

[Ron Green]

To check the coil take an ohm reading between the + & -- terminals when cold. For 6 and 8 cylinder engines you should be reading around 1.5 ohms or slightly greater. For 4 cylinder engines you should read around 3 ohms or slightly greater. Take another reading with the engine warmed up. A digital meter is much easier to reader then one with a pointer.

[Guest Ken G]

I know nothing about Cadillacs and prefer magneto ignition (!) but an ignition coil is nothing but a large-ratio transformer. If the internal insulation has broken down, either on the low-voltage side or more likely on the high-voltage side, it might have a short-circuited turn. That would greatly reduce the spark, although perhaps you would still get enough for the engine to run, but it would almost certainly lead to excessive dissipation i.e. heat in the coil. It would be interesting to know what the average current consumption is (measured with a good old-fashioned analog meter because the digital ones give useless answers on currents that are varying rapidly). It should be no more than two or three amps. If it is significantly more, the coil is faulty.

Ken G, 1925 Rover 16/50 (San Francisco)

[Ron Green]

Measuring the resistence (ohms) works just fine and a decent digital meter will also have a bar graph somewhere on the screen. I have done it many times checking coils and if there are breakdown issues, etc in the windings the meter will pick it up ohm wise. I always do a cold then warm / hot test as on occasion when things get hot they separate or resistence goes up throwing readings out of tolerance.