What's Causing My Car's Black Smoke and Stalling Issues?

[FishmanGeertz]

When I start my car (a 1972 Lincoln Mark IV) a plume of thick, foul smelling black smoke comes out the exhaust. About ten seconds later my car stalls, I start it back up for it to repeat this process about 3-4 times until I can finally get it going. It also stalls whenever I change gears. Why is there so much black smoke billowing out the exhaust? Why does it keep stalling a few seconds after you start it?

This car was given to me by a close relative. I don't have the money right now to get it looked at by a mechanic.

My car also backfires quite often.

What could be causing this?

 

[Unrest]

Black smoke when you startup can mean leaky valve seals. While it's parked, the oil in the head seeps down into the cylinders. So when you start it, it all burns at once.

All that oil could be clogging the spark plugs and making it misfire or stall.

Misfires can lead to backfires as the unburnt fuel is sent out the exhaust pipe and ignites there instead.

So I'd check your spark plugs first, that might offer a temporary quick fix. Could also be carb problems, timing, vacuum leak, etc.

 

[hypatia]

I would agree with Unrest, you are burning oil.

 

[Ranger Mike]

you sat the car was given to you by relative...how long has it been sitting? where was it stored? any idea if it was driven weekly? monthly?

 

[FishmanGeertz]

you sat the car was given to you by relative...how long has it been sitting? where was it stored? any idea if it was driven weekly? monthly?

No idea, it's in pretty bad shape and was probably poorly maintained. It needs a ton of work. The money I would put into fixing it up would probably buy me a new car.

 

[S_Happens]

If it was burning oil, you probably wouldn't describe it as black smoke. It is usually noticeably blueish, sometimes almost white, but almost certainly lighter colored smoke.

Other than that I agree with everything Unrest said.

Pull a plug (or 8) and post pics.

 

[xxChrisxx]

Black smoke is usually very rich running isn't it. Oil is blue/white.

Which probably explains why you are getting it at gear changes as well as starting. It's a fairly old car, so check the choke and make sure it's not jammed open. After that it's the carb that probably needs a rebuild.

Does it feel like it's running on less cylinders than it's supposed to? Overly juddery, sounds dreadful. Pull the sparkplugs, you'll find there probably caked with crap, or melted.

 

[Ranger Mike]

FishmanGeertz
do not think it will cost price of a new car...
there are many things you can do with limited tools and basic knowledge to get the car motoring properly.
the VERY first thing to do is to remove the air cleaner and check the air inlet passages. many times there is a duct work to outside fresh air on these older cars..these make perfect living conditions for mice, small birds, insects...i found a birds nest in an old car left over the winter..hence my question about the cars storage history..check it out..and check the air filter by placing a trouble light ( light bulb with recepitcle on an extension cord) inside the paper air filter element..if you can see a lot of light through the element, it is probably not too clogged with dirt.
this is step one..check for restrictions regarding AIR FLOW

 

[jack action]

Black smoke means air-fuel mixture is too rich.

I would go with Ranger Mike's advice: start with checking air flow restriction. Remove the air filter and try running it with the carb taking air directly. If it works than you have a restriction somewhere in the air duct (dirty filter?).

But, most likely, the car was unused for a long period of time (6+ months) and the http://www.sterndrives.com/old_fuel.html" . Probably the needle (#58 on the drawing, connected to the float #56) that is full of varnish (or other debris) and stay open constantly. Carburetor probably needs a rebuild (clean-up) as xxChrisxx said.

 

[Ranger Mike]

excellent advice action jack and chrissxxx..
carb would be next on the check list...and drain old gasoline from the gas tank..
(Use on bon fire for Earth Cat when you burn old tires and engine oil to celebrate Mother Earth and honor Gaia)

 

[FishmanGeertz]

FishmanGeertz
do not think it will cost price of a new car...
there are many things you can do with limited tools and basic knowledge to get the car motoring properly.
the VERY first thing to do is to remove the air cleaner and check the air inlet passages. many times there is a duct work to outside fresh air on these older cars..these make perfect living conditions for mice, small birds, insects...i found a birds nest in an old car left over the winter..hence my question about the cars storage history..check it out..and check the air filter by placing a trouble light ( light bulb with recepitcle on an extension cord) inside the paper air filter element..if you can see a lot of light through the element, it is probably not too clogged with dirt.
this is step one..check for restrictions regarding AIR FLOW

Maybe the price of a 7-8 year old used vehicle. My best friend's brother is a mechanic and he said he'll take a look at it.

 

[Ranger Mike]

let me know what you found..never too old to learn something...and this is a great place for it

 

[Fahlin Racing]

Sounds like your carburetor is in need of cleaning and a new set of gaskets. If you have extreme amounts of hydrocarbons, you have either a what has been mentioned already (air flow restriction) or a bad gasket allowing fuel to enter the induction tract in the wrong manner. You should be able to smell the gasoline on the plug and see fouling on the electrodes if the rich of stoich is at the extreme point.

The money I would put into fixing it up would probably buy me a new car.

Most likely not. Carburetor kits are not expensive, you should be able to get by with spending less that 100 bucks easily to get it in running condition just by replacing the simple items. I don't think you have any special carb besides a Holley or a Motorcraft. Being a 1972, I am thinking you have the 460 385 series Ford engine.

Now if you are speaking of replacing panels and paint etc, yes the project does get to be expensive. Just have to have the right resources for getting parts it doesn't hit the wallet hard. Sometimes, repairs are cheap if you have a good friend that is mechanically inclined and has bodywork skills.

 

[mender]

When I start my car (a 1972 Lincoln Mark IV) a plume of thick, foul smelling black smoke comes out the exhaust. About ten seconds later my car stalls, I start it back up for it to repeat this process about 3-4 times until I can finally get it going. It also stalls whenever I change gears. Why is there so much black smoke billowing out the exhaust? Why does it keep stalling a few seconds after you start it?

It's flooding (too much fuel).

What could be causing this?

The choke isn't set right or isn't opening properly.

Next time you start the car, have the air cleaner lid off and check the choke plate to see if it opens after starting. It should have a vacuum operated choke pull-off (#2 or #4 in the above diagram) that partially opens the choke plate right after starting. Ford carbs had a tendency for failed diaphragms in these pull-offs.

If the choke doesn't open at least part way, grab a screwdriver and prop the choke open and restart the engine. It should run reasonably well on its own now and without belching black smoke.

After the engine is warm (5-10 minutes), the choke plate should be fully open on its own. If not, the choke thermostat isn't working. For now you can adjust the choke mechanism so that it is fully open. Loosen the screws holding #13 and rotate while holding the throttle partly open (engine off) until the choke plate is vertical.

You should also check the spark timing, backfiring is usually a symptom of late timing. Given the year of the car, I wouldn't be surprised if the timing chain is very loose, possibly enough to have skipped a tooth. If the spark timing is out by 10+ degrees, there is a good chance that it skipped.

To check the timing chain, pull the distributor cap off and using a deep socket and breaking bar on the damper bolt, rock the engine slightly while watching the rotor in the distributor. If you can move the crank more than about 10 degrees (look at the timing marks on the damper) without moving the rotor, you definitely need to replace the timing chain.

If you do need to replace the timing chain, you can get rid of the factory set that retards the cam 4 degrees by using an aftermarket timing set; it'll help the engine make more power and get better fuel economy.

While you have the distributor cap off, twist the rotor to see if the mechanical advance mechanism is moving freely; it should return to the original position when you release it.

The list can go on for a while; let us know what you find. Letting this go will cost you lots of money in extra fuel and can damage the engine, so get your buddy's brother over as soon as you can. And remember, cars usually get parked when they need work.

 

[Ranger Mike]

some very good advice from Mender!