Ok I do not know much about reading plugs. To be honest I don't even know if it really even applies to modern fuel injection engines. So if I am wasting your and my time please let me know.

Let me now start by saying it is not that easy to find in depth information on plug reading. I can always find the basic info like what ngk has on there website but really getting down to the specifics of plug reading is not readily published all in one place.

Earlier today I pulled 2 plugs on my 1999 frc to see how new they were being that I just bought the car. When I had them out they looked newer and not in need of replacing at this point. But when I was inspecting them I did not like what I was seeing (if I am even reading this plug right).

What it looks like to me is
1. The timing mark on the electrode strap indicates to much timing
2. Possibly to rich at idle or plug heat range is to low by the color of the ring and first couple threads
3. The porcelain appears to be way to white and indicating way to lean under heavy load/wot.
4. One spot on both of the plugs almost at the end of the porcelain there was a darker circle about 1/4 the diameter of a pencil eraser ( could not get pics to show it).

 

Someone has to know something about reading plugs here

 

That plug looks brand new. Are you evening getting any spark to it? I'd start by testing for spark.

 

Car runs fine and is not misfiring but when I pulled the plug it just appears to be way lean. I was looking for some input on the fuel mixture

 

I thought to read plugs correctly you have to do a wot pull, kill the motor then check?

 

2 things you could do. Get a wideband or go to a shop with a dyno and get your afr readings.

 

You may be right that is whi I am asking for input.

 

From what I understand reading plugs is more accurate if you know how to do it. Plus it is free!!!!

 

Reading a plug is somewhat subjective and open to interpretation. A wideband O2 meter on the other hand, provides hard numbers with regard to your air fuel ratio. If your plugs look relatively new, you aren't experiencing a miss or a knock and your fuel mileage is decent, what are you trying to accomplish?

 

Free is correct, accurate is NOT. You can get a good feel for lean/rich by reading the plugs, but you cannot be more accurate than the computer. A dyno will show exactly what is going on, at what rpms things are happening, and so on. At best, reading a plug with your eyes are nothing more than an educated guess. On a high HP motor, too lean = BOOM! Don't guess, get on a dyno. If your motor is stock, there is more leniency. The more HP created, the less tolerance.

 

What your said is true and I will not argue with you but wide band sensors can also be out of calibration. Mainly i was hoping for someone to help me learn how to read a plug so I know what I am looking at. Currently my car is stock aside from a axle back exhaust and it runs fine but the plug indicated that I may be running lean. Regardless of modded or stock it would be nice to be able to accurately read my plugs when I change them (kinda like a health report/checkup). I would never tune a car by looking at a plug unless it is using spray. Wide band sensors can not accurately read nitrous and the only way to truly tune it in is by reading the plugs.

 

Fair enough. Let's say your reading of the spark plugs indicates its running somewhat lean. How are you going to fix that? With the computer. Gonna have to hook it up to correct the AFR. So instead of guessing, just use the computer to read AND fix. No muss, no fuss.

 

Google it. Lots of pictures showing various spark plugs and what they mean. To me those look brand new. You said nothing is wrong but you pulled the plugs anyways. It's as if you're looking for things wrong so that you can fix them?!?

 

If you think your running too lean pull your codes not your plugs... it's free and easier

 

Reading plugs is something us old timers had to do.We looked at the plugs to see if we needed to adjust the carb,change heat range of plug,etc.Today they have calibrated diagnostic equipment to check the engine to see if it is in the proper parameters.If you think your plugs show an issue, then you still will need a computer to diagnose and make adjustments.For peace of mind you may as well let a professional tuner look at the car.Personally i think the plugs look fine.

 

I have no engine dtc's and may not be lean. I never thought it was lean until I pulled the plug as I just bought the car and wanted to see how old they were. I understand that a tune can correct afr's but if the car is stock I should not have to get it turned to correct any problems it has. I am going to check the fuel pressure any way because I believe the the pump is getting weak due to the fact it takes to long to prime when starting. If I let the pump prime it fires right up and if I just try to crank it right away it takes a couple revolutions to fire.

 

Just give it some time. You will probably have real problem to deal with sooner or later.

 

When you say it takes a long time to prime the fuel pump how long is too long for you? I think you're developing a case of car hypochondriac. lol It is perfectly normal for the car to hesitate starting before the fuel pump has primed. Unless it's taking 10 seconds to prime I'm sure you have nothing to worry about.

 

No car should take 10 seconds to prime the fuel pump. I would say it probably takes 3 to 7 seconds to prime which is excessive. I wanted to look into the fuel pump b4 I looked at the plugs they just gave me more reason to look in to it.