Need help with spark plug diagnosis

[alkon]

I have a 91 Camry LE with 180k miles. Recently, it has been running as if it lacks complete power. This morning I began to look at variious aspects of the engine to determine the problem. When I pulled the spark plugs, I notices that all of them had good appearance (light gray in the firing area) except for one. My #2 plug has a medium brown coating on the electrode and ceramic area surrounding the firing tip. It is not oil fouling. I am running Bosch Platinum plugs.

What would cause this?? Would this appearance of the plug idicate that the plug does not fire at all... or, is it firing inefficiently. I changed the plug wires about 8 months ago with Toyota OEM wires, therefore, I can't imagine there is a problem there. Additionally, I conducted a compression test and got 170 - 175# on all six cylinders... including #2.

[Gary_602Z]

I know a lot of people don't like Bosch plugs. I am not sure if that is your problem or not but it would be an easy try. Did you replace the plugs when you did the plug wires? Pesonally I would say the plug is firing okay. If it was a bad missfire on that cylinder it should be more black.

Let us know what you find out.

Gary

[barthmonster]

I recently went to NGK Irridium Plugs and at the same time replaced my old, cracked Accel Plug wires (I have no use for Toyota OEM wires) that were 8 years old with NGK wires from www.importcarparts.com. The change of both of these items on my '94 with 233k made a world of difference!! Runs great!!

[Nad1370]

Sorry but you have to get NGK's in there before everything. Bosch platinums suck on toyota engines.

Change it and see if it changes.