hi
i have a x-type 2.ol 2002 petrol my fuel pressure was 4.5bar, the pressure was released a little accidently and
now its 4bar, is that ok? and if i drive it a bit will it become back to normal or just stay at 4bar?
and if its at 4bar will it damage? thanks returnless fuel system please reply

 

The fuel pump will bring it into normal range as the engine runs.

 

Zibby, please keep in mind that the fuel rail pressure is a function of the intake manifold pressure. So, if you measure the fuel rail pressure with the car running and with it not running, it will be about 10 psi (or 0.75 bar) different. So, that along can account for what you are seeing. Now, with that being said, the fuel rail is suppose to run 40-50 psi (2.75 to 3.45 bar) with the engine running. So, with your reading up at 4 bar, that is still good to a certain point. It is still over the minimum of 2.75. But, what you may experience is a drop in mileage because the computer is assuming that the fuel rail is running in a certain range and it knows that the fuel injector will flow a given amount of fuel for a given amount of time the injector is commanded to open. With this information, it can calculate the amount of time needed to keep the injector open to match the amount of fuel to the amount of air. With a higher fuel rail pressure, you will actually flow a little more fuel than what the computer is thinking it is and therefore get lower mileage out of the car. Now, the computer will compensate for this somewhat as it is also looking at the exhaust and seeing how much fuel is making it out of the cylinder and therefore will alter the length of time the injector is commanded to open accordingly. But, it can only do it but so far.

Is there anything you need to be worried about with your car? No. But, if you are looking to possibly get a little more mileage out of the car, you may need to look at the fuel pressure regulator.

 

Thermo/Razkid thanks for reply
after 2 days drive the fuel pressure back to normal now 4.5 bar thankyou

 

thanks for you help i needed that answer about fuel psi look every where and no one didnt know.