Thread: nismo fpr question

i just installed my fuel rail and injectors as well as my nismo fpr, i rented a fuel pressure tester from advanced t'd it off from the fuel feed line, but when i hit the key to prime the pump the pressure goes to 30 something then falls down to ten or so. do i need to get a different/better gauge /tester, or do i have to jump the fuel pump relay so the pump stays running or do i possibly have a leak? thanks

Set the fuel pressure with the car running. If you jump the relay the battery voltage won't be where it is usually when the car is running and the pump won't be running at the right voltage which could impact the fuel pressure.

Make sure your fuel lines are hooked up correctly. If you have them reversed you will build but then quickly lose fuel pressure.

Set the car to 43 psi fuel pressure with the car running and the vacume line off then plug the vacuum back in and you should be set. It could be that the pressure is dropping because the pump only primes for a few seconds then shuts off.