Read my spark-plug

[Basoline]

Ok, can you guys "read" my sparkplug for me? This one is from the front cilinder, driver-side. We also checked one from the other side, but that one was chocolate brown-ish. So that should be okay right? But this one is slightly colored brown on one side and grey on the other side. Thanks!

Symptoms to keep in mind:
- she runs hot in slow trafic and trafic jams (despite 3 core radiator)
- she reacts slow on throttle
- she runs "nasty-ish" on idle

 

[bonzoro]

I read your plugs

Looks like it may be running lean, could explain the heat problem along with the rough running. Did you check timing and set your carb correctly? Thats the wonders of running with a narrow/wide band o2 sensor ($150 Split Second.com). It makes it real easy to deal with the tuning problems on the cheap vice a 3-500 dollar F.A.S.T system. Start with the timing and then work from there on carb tuning. Are you running a Vacuum Advance? What jets do you have? What ignition system are you running? What kind of manifold (single/dual). Alot of things can contribute to rough running. Open the hood at night and look for sparks from the wires arcing, check for vacuum leaks with a can of WD40 (less flammable than others). Aluminum radiator or stock? Just a few things to check. I run a Procharger and my plugs indicate rich which is where I need to be, and then again, my eyes aint so good anymore and somebody else may tell you that the plugs look fine. Either way, rough running is NOT normal and these are some of the things you NEED to check. Thanks

Perry

 

[stappy]

Ditto on the coloration. The other problem is that pictures on my monitor may not look like your monitor which may not look like his monitor. Don't even get me started on what it may look like out of a printer. Unless all monitors are calibrated to the same standard (they are not) the picture will look different on every one.
That being said... The way it looks on my screen is lean. I would take the actual plugs to a knowledgeable (most likely non-chain store) mechanic (preferably older guy who knows carbs = over 50 years old) and have him read them.

Also, maybe you need to put in the orange or red spark plugs, not those blue ones :icon_winkle:

 

[socref68]

Timing,or carb will not effect one cyl. the plug you show indicates little or no fuel to that cyl. Check compression, spray some WD40 around the intake man.
check for any vacuum leak close to that cyl.
If the plug was wet when you removed it, check to see if you have spark.
Hope this helps.
PS Been a mech. since 1954 owned lots of Mopars, currentley have a 1967 Dodge Charger With a 383.

 

[spoiledrottenauto]

Check out these links from an old school mopar racer who is EXTREMELY knowledgeable with just the tuning aspect of our old beasts. He works a lot with ignition and carb tuning issues and can custom curve your distributor based on a huge database of engine combos etc. He is very helpful and available to help.
http://www.4secondsflat.com/plug_chart.html
http://www.4secondsflat.com/Spark_plug_reading.html
Hope it helps. I learned stuff I never heard of on the second link!
Brian

 

[Basoline]

Guys thanks for the replies! As usual, I was not complete in my description:

- the sprakplug was not wet
- the color of the shown plug is coffe cream brown
- I have a electrical ignition with chrome ECU and MSD coil with vacuum advance
- intake is an Edelbrock dp4b
- Carb is an Edelbrock 600cfm

We checked the distance between the rotor and the "thing-I-don't-know-the-name-of" inside the rotor.

Timing should be okay, but swapped tranny from auto to manual (flywheel -> more mass?).

I know it's difficult to diagnose, but anything you guys tell me is something I could learn...

Thanks!

 

[HitIt]

Check out these links from an old school mopar racer who is EXTREMELY knowledgeable with just the tuning aspect of our old beasts. He works a lot with ignition and carb tuning issues and can custom curve your distributor based on a huge database of engine combos etc. He is very helpful and available to help.
http://www.4secondsflat.com/plug_chart.html
http://www.4secondsflat.com/Spark_plug_reading.html
Hope it helps. I learned stuff I never heard of on the second link!
Brian

Wow what a great link, thanks for sharing.

 

[Meep-Meep]

Yeah, it does look a bit lean on that cyl. You are running a DP4B dual plane so compare the plugs that correspond to the cylinders being fed by the right or left plane of the intake. In some cases the vacuum hose connection only goes to one plane and if it leaks 4 cyls will run lean (assuming you have this). Or you may have some other leak or a weak mixture at the carb. Pulling plug wires out of the dist cap while the engine is idling is also a good way to check for mixture strength. Is your intake heat crossover open or blocked? Inlet mixture temp will also affect how it runs.

 

[Basoline]

Great links and great feedback guys!

Intake heat crossover is open.