Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance measureing fuel pressure

For those that read my fuel pressure post in FI I am trying to figure out why I only get 30psi at idle with new FSVT pump, new filter, new pressure sensor. I am told I should be getting 40 psi at idle...and I assume that is with vac connected.

Well, I have been doing a ton of reading on various forums and some corvette guy has me second guessing the method I used to measure my fuel pressure.

I have a returnless system and at idle I get 30 psi and if I remove the vacuum line from the pressure sensor on the rail it rises to 40 psi. Am a suppose to take the number with or withOUT the vac line attached. This guy was saying that the PROPER figure is with the vac disconnected.

Anyone have the definative answer on this one?

This doesn't make sense. The 2000 with returnless does not have a fuel pressure regulator. Fuel pressure regulators are on the return side. Returnless = no return side. The returnless system controls fuel pressure from the PCM.

Would someone let me know if my memory is faulty?

You are correct about no pressure regulator, however, there is a fuel pressure sensor that feeds info to the PCM that does have a red vac line attached to the bottom of it.

Use your scan tool to check the FRP_PID and compare it to the mechanical guage reading.

According to the PCED, KOEO and hot idle fuel pressure readings should be around 50 psi with the pressure reading around 39 psi at 30 and 50 mph. There is no qualifying instruction to remove the vacuum line anywhere in the testing instructions.

Steve

thanks steve...gonna give it a shot. i have not used the scan tool to measure yet, just two differenent mechanical gauges