I just recently replaced the heads, new plugs, new cap, new rotor, wires etc.

I pulled the plugs today to see how the motor was doing and the #3 and 4 plugs are black. Not wet oily black but exhaust/carbon black. The other plugs are fine looking.

I'm wondering what would cause this on just the two plugs?

 

Rotor and inside of the cap look fine also.

 

EA82, auto

sounds like the seals around the valves havnt been broken in yet its letting enough oil in to foul the plugs yet it probably still fires on those cylinders if I were you I would check it again after putting about 500 miles on it.

sounds like the seals around the valves havnt been broken in yet its letting enough oil in to foul the plugs yet it probably still fires on those cylinders if I were you I would check it again after putting about 500 miles on it.

 

Oh, I've put at least that! I'd say closer to 1000 miles.

Are the vavle stem seals new?

 

GD

Are the vavle stem seals new?

 

GD

 

Yes, the heads were rebuilt, machined, valve ground etc. New stem seals...

Next question. Carb, SPFI or MPFI?

Next question. Carb, SPFI or MPFI?

 

Carbed.

 

BTW what happened to the signatures? I had all that info written into my sig and it doesn't show up anymore.

Carb it is, I was thinking so. Not saying this is your problem, but it could be. Seen it on various Makes/Models of carbed engines.

 

Possibility of to much gas here. Either the float level is to high, needle valve worn, float is defective, piece of junk holding the power valve open. All will allow more gas into bowl than what's suppose to be in there, except the power valve, (it'll want to drain the bowl). Extra gas is going to the 2 rear cylinders, due to the slant of the engine mounted in the vehicle. Gravity takes effect here.

 

On V-8's it'll fowl the 4 center plugs, In-line 6's = 2 center plugs, same on in-line 4's. Just stands to reason it would effect the 2 rear plugs on a flat engine.

 

Just my .02.

Carb it is, I was thinking so. Not saying this is your problem, but it could be. Seen it on various Makes/Models of carbed engines.

 

Possibility of to much gas here. Either the float level is to high, needle valve worn, float is defective, piece of junk holding the power valve open. All will allow more gas into bowl than what's suppose to be in there, except the power valve, (it'll want to drain the bowl). Extra gas is going to the 2 rear cylinders, due to the slant of the engine mounted in the vehicle. Gravity takes effect here.

 

On V-8's it'll fowl the 4 center plugs, In-line 6's = 2 center plugs, same on in-line 4's. Just stands to reason it would effect the 2 rear plugs on a flat engine.

 

Just my .02.

 

That's deep man.

So that's more than what a can of carb cleaner will fix. Anything I could check for myself? I've heard these carbs are a Mother to work on.

 

Mmmm.... come to think of it, the carb was supposedly rebuilt just before I bought it.