OK here it goes I have a 91 da9 integra with a mildly built b20vtec pr3 head running on p30 ecu with aem 40psi fuel pump, aem fuel rail, and spector fuel pressure regulator. Car runs **** at super high rpm and super high mph but I'm only getting about 10-15 miles per gallon city and not any better at highway speeds. I've checked all fuel lines and filter and I'm only running at about 28-32psi at the fuel rail. Don't know why nor do I understand why I'm getting such shitty gas mileage. Any and all suggestions and advice are welcome and very much appreciated thank you

 

Are you burning oil?

 

start with giving it a tune up.
then get the vehicle tuned for what it is.