Where are the spark plugs located on a 1991 Toyota Camry?
follow the wires. on toyota's they are usually on top of the engine inside "holes".(don't know why in hell would they do that) On ours, the cover has EFI on the top in big letters. And I don't know why they put the things in holes either. Makes them pretty difficult to get at! I am not 100% sure what your engine looks like cuz nobody said what they were talking about. But I will assume that whatever one it is, it has the deep recessed hole with the sparkplug at the bottom. It is surrounded by valve cover. If this is the case, the reason is that for best combustion (ideal flame-front propogation and alla that complex stuff ) the plug just simply *has* to be in a particular spot in the combustion chamber. And on many engines, this just happens to be between the valves, and the *only* way to get there is through the valve cover. But nobody wants to have to pull the valve cover off to change plugs, so they made a 'well' for it. This was the same on my 1974 Toyota Corrola, my 1964 Peugeot 404, my 1962 Peugeot 403, my 1952 Chrysler hemi, my 1996 Chrysler V6, my 1998 Toyota Camry.. many, many more (but who cares?)  All this for cleaner running, better mpg, and power.