Read plugs, running rich, where to start?

pachecoj

New member
I know it is a total newbie question, but I am a total newbie with engine work so bear with me.

I pulled my plugs last weekend and read them. They were sooty with some carbon deposits, indicating that the car is running rich. Also, the air filter smells of gas, which would coincide with a rich mixture.

I don't think it is too bad because I'm getting about 19-20MPG, but it could be leaner. My first question is, where do I start? Given that I am a total newb I'm looking for basics here, like I suppose I should check the timing. I'm sure the carb is a bit out of tune so I could try rebuilding it, but I've never done it before. I had replaced all of the ignition components (plugs, wires, cap, rotor) a year ago when I first got the car. The car starts a little hard, but once it smooths out it idles and drives nicely.

The other question is, since the plugs are basically brand new I would like to continue using them. Is there a good way to clean them off so that I can read them again after making adjustments? I've tried lightly wirebrushing them with a stainless steel brush but they are still pretty sooty.

Jason
 
'71 Comet, 200c.i., Carter YF, stock points-type dizzy. Everything is stock. All new ignition (except the coil) and charging system components.

Basically I'm looking for basics. That is, if a car is running rich, what are the first things to look at that could cause this.

Jason
 
Don't tear anything apart yet.

Look at anything that can restrict airflow into the engine. I.E. the aircleaner, and the choke.

The aircleaner should be clean. You should easily see light through it when holding it up to a 100W incandesent light bulb. Compare it to a new one to see the difference. A dirty aircleaner will make the engine run rich.

The choke should close on throttle opperation when the engine is off and cold. It should open about 25% or so when the engine is running and cold and open completely and stay open when the engine is warm.

The idle mixture screw can also be adjusted but be careful to count the turns you make in 1/4 turn increments so you can return to where you started. This should only be done after a full tune up. There are lots of instructions for how to adjust your carb on this site. I do it by feel and have had good luck with that methode. You will have to discover what works best for you and stick with it.

You don't say how much driving you have on those ignition parts but if it is a full year of driving I would recomend replacing them all as cheap insurance.
 
as for cleaning the plugs, try something like acetone and a brush, just a brush isn't going to do much
my dad used to sandblast 'em sometimes, but that's a bit much

a solvent should help

if you're sure you fixed the problem, you could just make sure the contacts are clean, and eventually everything would burn off
 
The choke could be part of the problem. I have been having problems with the choke sticking. I keep having to readjust the choke because it is getting stuck open or stuck closed.

I've taken the back of the plastic choke adjustor off and made sure everything is kosher, but the problem persists. I think I have to spend some time figuring out exactly what is causing it to do this.

Once I get things working happy I am thinking about doing a manual choke "upgrade".

Jason
 
Uhhh.....19-20 mpg is pretty good for a properly tuned/running 200 of that era. If you were running a different gear set with a five speed or something I'd be a little worried. I'm guessing the car is an auto with 2.80 or so rear gears? Our sixes pretty much run rich to lean. Ever have the valve seals done?


Ron
 
I've never had the valve seals done, but I've thought about it. I've also never checked the compression, which I should probably do at some point since I have a compression gauge.

Jason
 
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