static bool started = false ;
if ( touch sensor is touched && !started ) {
started = true;
start the engine
}
BUT...
YOU have to replace "touch sensor is touched" with the right thing, and
YOU have to replace "start the engine" with the right thing,
YOU have to come up with a way to set the variable started to false again or the car will never start again.
PLEASE PLEASE PLEASE read the locked posts about the correct way to post, especially about using the Arduino IDE to auto-format (CTRL-T on a PC) and using code tags.
Read oil pressure and only allow if the pressure is less than a set point. That way, if the car stalls, you can restart it without rebooting your processor.
And if it falls below the set point while driving? You have more than an errant starter to deal with anyway.
I think you need to put the code for checking the touch sensor in a loop and escape the loop when the touch is detected. It similar to how to use button to start program