Spark plug knowledge is essential

[joel.vargasph]

To make sure the ratio is within specification, I'll be installing a wideband AFR this coming weekend.In light of the fuel smell, the sooty spark plugs, and the economy, I think it's a little rich.

Will the sooty appearance burn off, or should I replace the current (almost new) plugs before starting the AFR tests and adjusting the mixture to get a clean baseline?
Can I still take my AFR test with the sooty plugs?
Can I use carb cleaner to clean the plugs?

Much obliged.

[ellie.hernandezej]

Cleaning black soot is as simple as using a carbo clean. Hundreds of times, without fail.
It is not a caked-glazed overheated plug.
Even though the soot will go away if you thin the mixture, it's best to start over when making adjustments.

Problems with ignition can also lead to inefficient burning.

[benjamin.cookca]

You can't put your faith in Amazon when it comes to plugs. Quite a few fake plugs have recently been circulated. Napa Auto Parts is where I get mine, but any big-box store selling auto parts should do.

[joel.vargasph]

Not on Amazon, but on the web (sparkplugs.com?), I discovered authentics and purchased sixteen of them.

After the ones with 500 miles will be cleaned and the AFR adjusted, I will replace them with new ones.

Much obliged.

[aria_dasu]

When cleaning plugs, don't use a wire brush; doing so can leave metallic deposits that could lead to a misfire. Avoid dropping them from a great height; media blast is ideal, but strong carb cleaner and scraping will do the trick as well.

If the plugs are still relatively new, an occasional grime shouldn't affect the accuracy of an AFR meter.

[joel.vargasph]

Used carb cleaner and a toothbrush to remove and clean the soot, which, thankfully, was not oily.

[joel.vargasph]

excellent starting point for tuning, and the coloration of the positive electrode suggests that the timing is almost perfect.

There was a significant amount of soot, although it wasn't quite enough to rule out the possibility of leaking injectors (which are brand new Bosch models).

[aria_dasu]

To obtain the most accurate picture of actual conditions, plug reading necessitates a complete shutdown and twenty minutes or more on the freeway. How much idling and driveway running did those plugs participate in?

[joel.vargasph]

There was no caking on, and a gentle tooth brush removed the surface grime after a "sprited" twenty-minute drive.

[astridtaylorub]

Put them back in, clean them, and give them an Italian tune-up. But before you do that, double-check the fuel pressure and the duty cycle of the air-fuel ratio to ensure that the WUR is functioning properly.