as a temp fix for my hot start I wanted to put a switch on the egi fuse, so that I can break the circut when the car is off when I will driving the car soon after shut down. by doing this will I cause a back up of pressure in the fuel injectors/ rail? thanks in advance.

 

Ummm... I have read that several times and still am not sure what the ACTUAL question is. Can you add a fuel switch? Sure, its been done hundreds of times.

 

by disconnecting the EGI fuse after you shut the car off it won't do a dam thing.... it's shut off on it's own when the car is turned off.