Fuel pressure uncertainty
 

I was told by Bill(?) on instant chat that ford tunes are all written at 39 psi. I had assumed that was what the spec would be under normal operating conditions, but my pressure with engine running and vac line attached is 29, and only jumps to 39 with the vac detached. Is this correct? I thought my regulator was bad but I installed a motorcraft replacement and it reads the same. Just making sure... thanks