Finally got around to installing an in line oil filled fuel pressure gauge. I've been having misfire issues for a long time now and have R&Red almost all ignition and fuel components without any change. Started to notice a stall at cold idle and decided to check the pressure. At idle and up to 4000 rpm NO movement on the gauge, needle is pegged at 0.. At 4000 it pops up to maybe 15lbs. The car can run and drive (poorly). How can it do that with no pressure in the line? Is this gauge (new from UK supplier, R-Spec Performance), a dud?

 

Fuel pressure should be 43 psi at idle and 46 - 47 on throttle up

The aft hose at the FPR is the return line back ( FPR dump ) to the fuel tank

Stall at idle , the first thing is main fuel filter change that does have O - rings inside the filter side fittings