decrease fuel pressure
 

I will wish to know if a pressure of 2,7 bars is normal on my FD (with Walbro 255l/h fuel pump)?

In addition it is normal that this pressure falls down all gently... i.e. that yesterday during the use of my car I had 2,7 bars of pressure and this morning there remained nothing any more but 0,6 bars.... Is this normal knowing that I do not detect a fuel leak?

Thanks for help

Yes, 2.7 is a normal base fuel pressure. No, the fuel pressure should not decrease over the day -- you have a leak, most likely an injector is dripping.

I noted that for some time I do not have any more pressure in the gasoline tank.... I does not hear any more gas leave when I open the ful tank cap. In addition I changed the O-ring of the injectors and the fuel dampner. When I make test of pressure I do not detect an fuel leakage on the circuit before and after fuel rails...

What do you think about it?

I think rynberg means the injector(s) itself is leaking. How many miles on your injectors?

It's not uncommon for the system to slowly depressurize - that's not a biggie. It is a biggie if you REALLY have to crank on the car to get it to start while it's building fuel pressure back up.

Dale

My injectors have 80 000 kms (around 50 000 miles). The car starts very well when cold but on the other hand much less better when hot (but I removed the double throttle system).

If you are having problems with hot starts only, start by checking the Fuel Pressure Regulator solenoid.