spark plugs black?

Question

i have newish spark plugs on my audi 80 estate it started to run rough so i checked the plugs and they had gone black and sooty, and i loose power. any ideas please

Answer 1

wrong mixture air and fuel, its not that difficult to sort out, but it might be your heavy right foot in an old car especially on cold mornings.

Answer 2

I will assume that since you have new plugs, your air filter is clean probably clean.

If that is the case and this Audi has a carb, when it warms up check that the choke plate is completely open. The plate is on top of the carb and will close off the entire opening when cold.
The float/needle valve in the carb could also cause dumping of gas into the intake, but you will usually smell the gas fumes when this happens.

If it has an injection system, then the injector is bad or the computer that is controlling it is bad or is getting the wrong signals from one of the sensors. Sometimes the engine temp sensor will fail and cause a rich mixture.

Answer 3

A car engine? A lawn mower? 2 stroke or 4 stroke or outboard or chainsaw? Air, fuel, compression, and spark . Missing one of those will not allow that cylinder to fire. Start by changing the spark plug with a new one and see if it continues to happen. Also, check the air cleaner to be sure it is clean. Is the spark plug wire on tight? We know there is fuel, so it should go. Unless it is a high mileage motor and you dropped a valve, I am assuming compression is present.

Answer 4

I believe your automobile (car) is running a rich mixture. Reasons are dirty air filter, dirty fuel filter, neglected oil changes, heated oxygen (lambda) sensor is not working, catalytic converter needs replacement, distributor needs replacement and the spark plug wires need replacement too.

Hopefully this will help on Audi 80 estate (station wagon), because I have a same problem with my car.

Answer 5

Rich mixture.

Is the choke stuck on (if it's got carb)? Air filter blocked? A black and petrol-smelling exhaust usually comes along with this.

Answer 6

First check that your air filter is not blocked IE when you remove it .it is very black and dirty on the inside face, If it has a carburetor have it reset or if you know were the mixture screw is, scew it in until the engine runs smooth, if that doesn't cure it there is a possibility its burning oil

Answer 7

Black suety plugs mean a rich fuel mixture
Black oily plugs, burning oil.
White porcelain plugs, lean mixture.
Master tech 40 yrs.

Answer 8

carb prob
air-fuel ratio
check out the Haynes manuel for the Audi 80 or something sim

Answer 9

The mixture is to rich meaning that the car is burning to much petrol and not giving the power.Bring to a mechanic and get him to set the mixture.

Answer 10

its burning too rich,ckeck the fuel system,also check the oxygen sensor and cat.if the cat is starting to clog up the the smoke will back up around the plugs.my car did that till i replaced the cat.