Ocassionally starts missing

i have toyota camary 1990 model with about 225,000Kms. for the last few days i am facing a problem , My car ocassionaly starts missing when it comes to idle on a signal or intersection. sometimes after that it stalls too. after that it starts perfectly but still it misses when i give it gas. it usually happens in the damp weather. i tried to fix the problem by spraying the ignition parts with silicon coating but the probem is still there. i have very less knowledge about the cars. when i consulted my mechanic he said he is not sure but he wants to try out by replacing ignition wires and rotor. Please help me by telling how can i fix it.

also have them check the distributor cap, wires, and plugs

If replacing the spark plugs, spark plug wires, rotor and distributor cap do not fix the problem, you probably have a hairline crack in the coil inside the distributor. This generation Camry is notorious for that problem. Your mechanic can replace just the coil with an aftermarket one. It's about $45 American for the part and probably less than an hour of labor. If you went to the dealer they usually want to change out the whole distributor for about $600 American for parts and labor.

Good luck with the problem.

Mike