my 93 lexus gs 300 has a hard time starting up.

what your mechanic told that was correct, If you want to check your spark plug wires spray water on the spark cable at night time while engine is running, you can see the spark will jump from your cable.You can check your distributor cap also. Regards K.Hasan

i had this same problem with my is300 my mechanics kept feeding me all sort oinfo and telling me to change different things all of which never worked until i changed the fuel pump assembly. to get to it u remove the backseat but it fixed everything hope this helps