Question on Spark Plug color differences

[inscarguy]

Hi all. I've been experiencing some idling and running issues with my 08 4.7. I bought it sight unseen but I got the vin prior to purchase and looked it up on Toyotas website for owners. It had a pretty good service history. Ever since I got it I've been chasing a strange idle and a huge delay when i press the gas pedal, much much worse than my '06.When it first starts I get a vibration that you can feel but goes away after about 2 minutes and sometimes idling in gear I'll get a slight roll. I've changed all vacuum lines with OEM, cleaned MAF and TB. Put in new injectors with 12 holes instead of 4. Did not change the plugs as they were just done by a toyota dealer. They also changed the complete air pump system. It ran flawless for about 5 months and came back worse than before. I cleaned and reinstalled the OEM injectors, checked grounds etc. Here's the possible issue, I pulled the coils and plugs. Some of the coils had a white residue on the outside of the boot. I'm thinking the boots might be porous whereas the spark is shooting out the sides of the boot instead of the plug. # 1, 3, 5, 7, 2, 8 looked ok except the porcelain was tan-brown. # 2, 4 the porcelain was pure white like they were just installed. I checked the computer for misfires and nothing. Any ideas?

 

[xtremewlr]

Discolored porcelain, possibly not properly tightened plugs or they were never replaced by the dealership. The boots are rubber, some white residue on them is normal. Check the coils for cracks along the extension going to the plugs, I bet some might be cracked and should be replaced with OEM or Denso only. Replace all the plugs with new when you re-inspect the coils. Plugs should be NGK IFR6T11 or DENSO SK20R11 with a .044 gap.