[65' I6] Black ash/smoke from exhaust, no power on cold start, bad mileage

[Nasko]

Recently I posted a topic regarding my engine's lack of power on a cold start, and got some replies that perhaps the choke butterfly is too open, letting too much air in. This may be the case, however, I did not mention that the exhaust also lets out A LOT of black gunk during cold start, and when stepping on the gas pedal, more black smoke comes out.

Is it possible that the carb fuel float is not working properly? It's an automatic choke autolite 1100.. carb tag is not there so I'm not sure which exactly. Also, lately it's burning more gas than usual, which is causing me to speculate that too much fuel is entering the engine from a bad float.

I'd like to get some help to diagnose the issue before I start taking anything apart. Thanks in advance.

[Dogface GI]

Have you pulled the plugs to see what they look like yet? What have you check so far?

[Nasko]

I checked just now. Plugs 1, 2, and 3 looked good. Plugs 4, 5, and 6 were pretty black and had oil on them. I know that's not a good sign! What else should I check?

[Dogface GI]

I'm no mechanic, so I'm hoping a more experienced VMFer will correct me if I am wrong, but it sounds like you may have a few worn rings. That would allow oil into the chambers where it would foul the plugs (oil on the plugs from the inside) diminish your MPG and be rougher than normal to start, when the engine is cold and lack normal acceleration when at operating tempurature. It would also explain the black smoke - burning oil!
If possible, take a picture of your plugs so others can see them and better diagnose what's wrong.
I believe a compression test would validate/invalidate this. You can get one at any auto store or tool store. Fairly easy instructions.

[Nasko]

Thanks for the reply! I'm not sure if this is the problem, as my acceleration goes back to normal as soon as the engine heats up in about 10-15 minutes. I will go get a compression test to check out the cylinders.

[LynnBob 65 Mustang]

Originally Posted by Dogface GI

It would also explain the black smoke - burning oil!

Oil burning would give you blue smoke NOT black smoke.

Blue smoke is oil.
Black smoke is from burning rich or something not firing correctly.
White smoke is water or coolant.


If it is black I would say you got a carb or ignition problem making you burn rich on those cylinders or something is not firing right on those cylinders..

If it is burning rich it will also cause him to loose power because the fuel isn't being burned as it should, thus no power and black sooty oily deposits on those cylinder plugs.
Lynn

[bartl]

+1 on carburetion problem, most likely a malfunctioning choke mechanism, although a weak spark/bad points can also do this.

[LynnBob 65 Mustang]

+1...
If you haven't done a full tune up on it lately, new plugs, wires, cap, rotor, points, coil, etc. do it now. Even if that isn't your problem, more then likely it is needed anyway if you have never done it since you got it or can't remember when it was done.

That would rule that out entirely and it is just not needlessly throwing money out the window as it should be done anyway as it is a preventative maintenance thing.
Lynn

[Nasko]

I recently changed the plugs, which ended up working horribly so I put the old ones back in. I ordered an electronic ignition which I will put in when it arrives.

For the oil on my plug threads, it might be because I've got a leaky valve cover gasket. I'm changing that today or tomorrow so I'll see if it helps.

Originally Posted by bartl

+1 on carburetion problem, most likely a malfunctioning choke mechanism, although a weak spark/bad points can also do this.

How do I regulate the choke mechanism? The butterfly seems to open during cold start. If I close it with my finger, the idle speed decreases. If I rotate the thermostat that would just change the rate at which the flap opens, correct?

[Blues Power]

sounds like you need a good carb set up incl all the linkages adjusted.

best bet is to get a chiltons manual and start thumbing thru it until you feel comfortable enuf to tackle the job.

I can almost guarentee that if you take it to a shop and if they dont employ an old timer most of em wont know how to do it correctly anyways
so better of learning yourself.