Help me fix my 1949 Cadillac

[Guest Ken G]

I'm sorry, Ron, but that is not the whole truth. Yes, if the problem is an intermittent or permanent open-circuit, simple resistance tests will reveal it, and hot/cold tests might be more revealing. However:

a) The present problem might well lie, indeed is more likely to lie, in the secondary, that is, the high-voltage winding, and that would not alter the resistance of the primary (low-voltage) one which would be correct.

A short-circuited turn (as I say, more likely on the secondary) would have negligible affect on the resistance measured with a meter (of either the primary or the secondary).

I think the simplest solution (if it hasn't been tried already) is to try a different coil, perhaps even to borrow one, although as I recollect coils are not very expensive.

As a side comment, cars in Europe have operated on 12 volts since probably the 1930s (my 1925 Rover is and my father's 1934 Morris Cowley was 12 V), and so coils intended for 12 V operation without ballast resistors are commonplace (I had to change mine on a 1968 Mini). Using a lower voltage coil with a ballast resistor which is short-circuited while the starter is operating has the virtue of providing a fatter spark during starting without over-heating the coil in normal running, but my suspicion is that the practice arose first because in the US at least it allowed existing 6 V coils to be used in the new generation of 12 V cars.

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

[Ron Green]

Ken,

For the record I don't disagree with your statements. For me if the coil is reading defective after I check the ohm readings and it is not within tolerance ohms wise I replace the coil. Typically this always has fixed the problem.

Many times I will also do a high voltage test before I even do the ohm test. There are various ways and test methods and equipment for this such as: http://www.handsontools.com/store/show_product/?product_id=1938 though I use a cheaper version. I didn't mention this to Emmanuel as many don't have this or any type of high voltage tester, but do have a ohm meter.

In any case for me this is what I have found to work the best. Everyone does things differently and I have too many vehicles to keep an extra coil for each.

[mrpushbutton]

I have seen some distributors where the wire lead that goes from the points, exits the dist. body and goes to the coil will develop a short to ground that can't be seen easily with the naked eye. Don't overlook that--with the points visably open and the wire disconnected from the coil check (ohm out) that wire to ground.

[Ron Green]

Good point. I have seen this wire rubbed to bare on occasion due to it being crammed into the distributor especially if converting to Pertronic's.

Also on some engines (Triumph comes to mind) there is a short ground wire from the distributor point plate that runs to outside the distributor to a ground. Sometimes this corrodes at the screws or will have an break in it that drives you crazy as it is intermittent . It works one minute and nothing the next.

[manncad]

Then, maybe I should check the wires from the points to the coil.

The ballast resistor I got did not take care of the problem. Coil still burning hot after 10 mins ride.

Also, anyone who knows where I can get an oil bath air filter for that type of car is welcome to let me know.

Is there any way to put photos on this forum. I could post some here and maybe you'll find the issue.

About the ohms or voltage check, I dont have the meters to do it, and I dont want to drive the car to another mechanic right now. But I will check as soon as I get one from someone.

thanks again

Emmanuel

[Ron Green]

Maybe your coil is ok even though it seems to be running hot to the touch?

I am unsure about 49 Cadillac coils however the coil in my Amphicar you can't even touch and I have tried several both old and new. At our national convention (64 cars) this was a major discussion so we felt a fair amount of coils after run in and they were all extremely hot to the touch. Seems this is just how it is with these cars.

Have a good weekend.

[manncad]

very interesting Ron. I called the guy who owned that car for 30 years ( my best friend now ) and he told me last night that the coil always been hot on the touch....so maybe there's nothing to do then.

And about the oil bath air filter, he said soaking it in gasoline would do nothing, better soaking it in lacquer finner and then burn it...which I'll try to do this morning, whithout burning myself hopefully....

Emmanuel

[Guest GP Gleason]

I wouldn't burn the air cleaner mesh. Some of those old oil bath air cleaners have a mass of jute to soak up oil to assist in the cleaning effort. It is usually packed into the top of the unit and is not easily seen. I was a mechanic for 45 years and always cleaned those air filters with cleaning solvent and a nylon bristle brush, blew out with compressed air and then air dried.

Be sure to check your ignition timing and also see if the exhaust system has a "heat riser" baffle. If so, and it is stuck partially closed, it could cause all your problems. It appears to me that you have carburetor issues.

If you could come across with an old (blue color) "MOTORS MANUAL" covering 1949 models there is a "troubleshooting" section in it which will help you narrow down your problem. There will be a series of diagnosis(es) for your exact problem. Good luck!

[manncad]

Thanks Gaugeguy,

you are right, I won't burn it as it is not made of steel mesh but more like a plastic mesh. The laquer thinner did take some of the durt off as it came out brown and durty liquid. I'm not sure what is a heat raiser baffle, but the exhaust system has been talked about in the this forum, and I don't know how to deal with it. The mechanic either.

I do have the 1949 Cadillac shop manual and read many times section 10, Engine fuel and Exhaust section, but it didn't help.

Anyway, my friend keeps telling the problem come from the metering rods inside the carburator, so he'll try to find me a new or rebuilt Carter Carburator as he comes visit in one month. Actually, if anybody here knows where I can find one....for cheap of course...I'll take it.

[rocketraider]

Last night we were talking cars and someone brought up a 1963 Chevy pickup that had much the same symptoms as manncad's car. Turns out the pickup had been changed over to V8 from six cylinder, by a Ford mechanic.

After several years of trying to diagnose the problem and toting a spare coil everywhere the truck went, someone finally realised the coil wasn't properly grounded, as the Ford mechanic wired the coil Ford style instead of GM.

This might be something to look at.

[manncad]

Well, I just looked at it and there is no ground at all. So what should I do to have that coil grounded ?

I never told you but I changed the entire wiring system myself 6 years ago, the car was running fine but I know Im not a electrical mechanic and I probably forgot several grounds wires. I know you will all think I'm stupid and should have done it better. I took each wire out, one after another and changed them by new ones.

One more news. I was in California last week for the funeral of my best friend Michael, the actual guy who owned that Cadillac for 30 years and who was supposed to come to visit in France and fix the problem.

During that time, I went to pick up an old 1949 Cadillac carburator. I'm back in France now and this morning, I put the metering rods of the old carb to the one I have on the car. It didn't change anything.

So, my goal is now to fix this cadillac for Michael, and drive it in his memory. If the ground is the problem, which could be, It will be the biggest laugh of all and luckly for me, Michael won't be here to laugh at me and tizz me, telling me i'm a loser.

Thanks agin for your help and waiting to an answer about this ground thing.

Emmanuel

[Guest pfloro]

Hello Manncad:

The secondary <span style="font-weight: bold">(high voltage)</span> side of the ignition

coil is grounded through the metal case of the coil. Make

sure that the inside of the metal clamp is clean & shiny.

I use emery cloth to also remove the paint from the coil

case in the area of the clamp. Use emery cloth to expose shiny

metal where the clamp attaches to the engine block (or firewall). <span style="font-weight: bold">

These tasks will insure a good ground for the secondary side of coil.</span>

As for the metering rods: I don't know this generation

of carburetors specifically but do know that metering rods

and jets go hand in hand. The brass jets are what the metering rods insert into.

The rods are tapered and regulate the air/fuel ratio based on the position of the

rods in the jets. Think of the jet as a donut and the rod

as a broom handle which tapers from a small diameter at the

bottom to a larger diameter at the top. I would transfer

the jets as well as the rods from the 'new' carburetor to the 'old'.

You may have jets which are too large in your

existing carburetor... This could create an overly rich

mixture...

Condolences on the loss of Michael. I think you are doing

a wonderful thing by keeping his memory alive through his

former Cadillac.

Please keep us posted...

Paul

PS: I have a Holley carb on a Ford Mustang V8 which had

jets which were <span style="font-weight: bold">too small</span>. The engine would sometimes stumble &

stall when moving from a complete stop. This problem continued even after

a complete carb rebuild. It took another sharp carb rebuilder to spot this hidden situation.

That car was a mechanical basket case when we first bought it.

Not any more...!

[manncad]

the coil is new and not painted. The clamp is new too.

So I guess it's fine, unless it's not enough to be grounded, and maybe I need a wire to go from the engine mount, where the clamp is bolted in, to...somewhere.

I'm so tired of this, probably small problem that I can't fix. I've done so much and still can't find it.

Why would this car suddenly run so bad after spending so many years running great. I've done something that I don't remember and now, I can't fix it.

Thanks for your help anyway

[Guest pfloro]

Manncad:

Speaking of grounds, check to see that your ground strap (or cable) from

the engine block to the body is also clean & tight at both ends. Sometimes

the crimps on the connectors to the wire (round or braided) become loose.

It doesn't take much electrical resistance to cause trouble.

Did my comments regarding your carb jets & metering rods make sense?

Don't give up. Sometimes, it's good to 'Let The World Take Another Turn'

before proceeding.

Paul

[manncad]

long time I havent answered on the forum, just to let you know I havent had time to deal with the car yet, I will do it as soon as possible to be able to drive it this spring.

cheers

[manncad]

Hi everyone,

I went to anither garage here in france, and the guy simply said I needed to get a new carburator.

So, if you can help me finding a CARTER Carburator for my 1949 Cadillac Model WCD 682 S

I sent an email to USA PARTS SUPPLY but still waiting for an answer.

Thank you

Emmanuel

[manncad]

Al right, I got a new carbirator , put it in, and the car is still missing. Maybe a little less black smoke, maybe run better on idle, but not the perfect and smooth V8 I've known for a long time....so I'm still working on it.

Later

[Guest simplyconnected]

You have already:

Properly grounded the distributor, coil, engine, and body,

Added a ballast resistor,

Checked the points-condenser wires for intermittent grounds (inspect very carefully).

Replaced wires, distributor cap, condenser, and points (& set them properly),

Timed the spark properly,

Changed and set-up a new carburetor & choke, and

Checked for blocked exhaust (not likely your problem).

There isn't much more to it, other than:

Make sure your spark plug wires are not crossed (VERY common - get the right firing order),

Make sure your valves are timed properly (camshaft to crankshaft timing needs to be mentioned),

Make sure; watch all your valve springs go up and down all the way (worn camshaft),

Make sure your valve lash is correct on all valves.

At this point, a compression tester is in order. You can mail-order one and they are easy to use. Simply remove one spark plug. While the engine is running, push the tester into a spark plug hole. You should read about 100psi on each cylinder. More importantly, all cylinder readings must be close to each other. If you have a cylinder leak, this tool will find it.

A heavy gas smell suggests too much gas is going into the intake. Black smoke proves it is burning. Spark plugs don't do well with RICH mixtures and often, they foul (flooded engine). Most times, after they dry out, they start working again.

Try this:

If you have 'vacuum-advance' on your distributor, make sure it is working properly. Do you have (vacuum) power assist brakes? If you do, disconnect the vacuum and plug the hose. Make sure your vacuum system is not leaking, then remove the air cleaner (temporarily). Take your car for a short (two to five mile) spin. Be careful on your 'trial' spin. Do it at a time when no traffic is around and test the brakes often to get a good 'feel' for stopping distance.

If your air and exhaust are unrestricted, you have proper mixture, and have properly timed spark, it should run very well.

As you button it back up, put things back, one at a time, with trial runs in between. You can isolate problems, using this technique.

Coil assemblies (coils) are oil filled, to evenly dissipate heat between the internal wires. Coils may run hot, but the real concern is your points. Are they wearing out too fast? If so, you can address the condenser and ballast (ignition) resistor.

Print this and check-off each item. Take your time. Let us know what you found. - Dave Dare

[manncad]

Thanks Dave for all your explanation.

I just took the Cad for a spin after putting my new carburator in. I didnt touch any adjusting screws.

The result is simple. The car starts great, no black smoke for 5 minutes, then car starts getting hot, black smoke appears, but not much. After 15 min, I drive and its not bad but not prefect as in the past. Then after 20 min, the coil is burning hot ( can't touch it by hand ) and the car is missing a lot, quite impossible to drive actually.

So, I guess I need to adjust the idle Mixture screws, also the fast idle cam, making sure the choke is closed when I do it. I also need to check if everything is properly grounded...but I'm not an electrician...maje sure the points are set right...ect..ect...

The ballast resistor doesnt do any difference, so I disconnected it.

At some point, I thought the firing order might have been the problem but I think it isnt. I guess it is 18436572, knowing that the 1 is on the bottom right as you are positionned in front of the car, number 2 is on the left, 3 back on the right ect....

About the vaccum, I have no idea if there is a vaccum power assist brake...There is some sort of vaccum on the distributor, and I never touch it.

I did touch at the advance and maybe I should adjust that again...only by hear as I dont have a timing light.

As the rest like plugs, wires, cap....it's all new.

til next time

I wonder if at some point, I should just ask your phone number to call you and you would guide me through the process.

I'm so tired of this situation, and I have to drive a couple getting married on July 12th....oulala

see ya

[manncad]

Hi everyone,

just to tell you some updates about the caddy.

IT FINALLY RUNS GREAT.

Yes, I found the right person to adjust the carburator, the points, the advance, to change a couple wires, move the coil from the engine block to the firewall. Now, the car runs smooth, doesnt smoke and doesnt smell like gas.

So I'm happy.

thanks again for your help and I wont forget the people who sent me parts from the US. Remember you will always be welcome here in my Chateau to taste some old Cognac.

Emmanuel

[Guest quadfins]

I am glad to hear of your success. I would like to see a photo of your car, maybe with the chateau in the background.

Best wishes,

Jim Eccleston

1961 Coupe de Ville

BATILAC