Here is my problem:
I live in a city that requires auto emission tests annually. I took my car
in to have the test done and it failed miserably. The hydro carbon count was
5 times the allowable limit. I was told that fuel is not burning as it goes
through the engine. The car has been idling rough and getting poor mileage.
My efficiency gauge lives at 3/4 to 1/2 what it should if running properly.
Does anyone have any idea as to what the problem could be? O2 sensor(the
light has not come on)? Bad plugs?
thanks for any help you all can throw my way.
Sounds like multiple problems...
First check all spark plugs for the condition of the electrode... what color
is it? Rusty white?
Seconds of all, your fuel mixture is too rich... this can be adjusted by the
fuel mixture screw but I wouldn't play with this unless I eliminate other
possible causes... such as spark plug wires (check for resistance about 1350
max ohm)... clean distributor cap and rotors contacts... inspect for any
damage, if so, replace them both.
Other possible reason is bad O2 sensor... what is the mileage? When is the
last time you changed one?
Well I have had the car for 4 years and i have not replaced the O2 sensor.
three years ago the engine was rebuilt after my timing chain broke. I do not
know if the O2 sensor was replaced. The distributor cap was firing away
nicely and did not look dirty. I have not checked the cables other than a
Why not? Isn't it possible that this is the only problem and it's just
seriously off? It'd be free and easy to check (3mm allen, stick it down in
the hole in the air filter top, engage in bolt, push down against resistance
of a spring, turn counterclockwise).
It's stupid to play with the mixture before verifying that the ignition
system is functioning properly...
You might cover up a problem, but you won't fix it.
After verifying the ignition system is working right, then using
proper gas analyzer or shade tree methods, the mixture can be adjusted.
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