All 8 contacts are identical regarding the burn/witness marks. Plug wire resistance is within spec. Plugs were 30k old. Standard Bosch WR9DC. No platinum or other odd ball stuff. Am I using the wrong sparkplug? Bosch website calls for a 7511 in Super which is a W9DC.
Is that (R)esistor difference causing a problem? WR9DC vs W9DC
What is a good source for conductive grease? It's worth a try.
S, J.R. Brown
2000 G500 LWB Obsedian Black
2005 Toyota Tacoma Access Cab Off Road Sport
1993 Volvo 240 Sedan Anthracite
1980 450SEL Champange (owned it for 15 years. Great car)
1986 280GE LWB Anthracite (Sold it and kinda wish I hadn't)