My 96 Camry 1MZ-FE V6 misfires on startup once in a while. The engine shakes so badly that it feels as if it's running on 3 or 4 cylinders. To cure it, I turn the engine off and restart immediately. Then it runs fine. The check engine light does not come on and checking with a scan tool shows no codes. Is this serious enough to indicate that one day I might not be able to cure it? Any ideas what causes it?

Spark plugs (most likely)
Spark plug wires
vacuum leak
EGR valve dirty
EGR VSV valve malfunction
fuel pump (least likely)

Use a scan tool and see if you get any pending codes.

Spark plugs (most likely)



agreed

pull them out and see if any of them looks different than the others. for the rear three, might be easier taking the intake manifold off to get to them instead of trying to work around it.