Odd sprk plug reading.

[spooldup]

This picture is what two of my spark plugs look like. The plug on the driver's side closest to the firewall and the middle one on the same side have this. According to the plug arcticle i read this is due to a dirty intake, injector failure, or dirty injectors. All of the other plugs look fine. If something was bad or dirty wouldn't they all look like that? Any idea what is happening here? Just to cover any basic questions, the intake is clean, brand new pte 50's, with a new walboro. In case this is not clear i am reffering to the black residue on the insulator.

p.s. This is not actually my plug :roll:

 

[92Ty#1524]

Im kinda stumped myself. Looks like the carbon residue of an impurity (unburned fuel, oil, foriegn material ingested through the intake). There are a variety things that would cause inconsistancies from cylinder to cylinider. But, assuming that there hasnt been a noticeable change in performance, you may save yourself wasted effort by first determing whether whatever happened was a one time thing or a progressive failure of some sort. Put new plugs in and check it periodically. If it comes back, then start using process of elimination to find out (A) why it isnt burning correctly (ie, ignition issue) or (B) from what 3 doors is this noncombustible substance entering. This is where you get into compression testing and such. How does your exhaust look? Any unusual change in coolant overflow reservoir level? ...oil consumption? How many miles?

Jack

 

[spooldup]

ok i did some homework. The compreesion in the 2 holes is 155-160. Zero oil consumption and coolent looks fine. There is 25k on the motor. The plugs are new as of yesterday. I pulled them after one run. My ty does not blow smoke. As far as doors are concerned i have no idea where to look. I don't understand how there is a difference? I don't know enough yet about the internal workings of an engine other than the basic's. The wires are atr's and they are new as well as the cap and rotor. O and it seems to happen all the time. I just my irridium's out after about 200 miles and it was on there too. I have kr problem that does not seem to go away. I am sure in some way this is linked.

 

[Hu Ryde]

If you have a KR problem this is where you should start looking for answers. The substance on the plugs to me looks like oil. Oil is a know factor that causes knock. Let the truck sit for a while and start it up look back and check to see if blue smoke comes with a cold start. If it does then your valve seals could be bad. During instillation they can be pinched and if they are they will not fully seal all the oil out. And over time it will leak oil down the valve and out. If it leaks down the valve and piles up on a closed valve it will burn when you start it up after sitting for a while. So, if you have blue smoke after the truck has sat for a while then you have valve seal problems. Check that. HTH

 

[spooldup]

The valve guide seals are brand new and the Ty does not blow one drop of smoke. This is what's confusing me. I don't have any signs of things that are bad/wrong.

 

[leroy]

A couple of things to try: switch injectors around to see if problem moves, leakdown test.

It's not clear to me from the picture, but it does look more like oil to me. Rich condition would show up more as a sooty look.

Jim

 

[spooldup]

thats a good idea. I will switch injectors today.