Describe your particular symptoms. Does it crank but not start? Does it not crank when it's hot unless you cycle the switch many times? If that's the case then check the EFI relay behind the battery. These can go bad from heat soak and give an intermittent failing. Here is a link to the online wire diagram on the starter circuit page. http://cygnusx1.net/Supra/Library/TS....aspx?S=D&P=32