Can you test the fuel pressure on the fuel rail?

There is a fitting on the back end of the fuel rail with a black cap on it. Can I test the fuel pressure here?

I have tested the pressure back by the fuel filter, but did it with the fuel line disconnected and just turned key to make fuel pump kick in. I got 41 psi. But I think I may still have a problem, so I'd like to test the pressure while vehicle is running. Is there another way?

You would need to place a tee fitting in the fuel line so you can have the fuel line connected while also having the gauge. If you wanted to test it at the fuel rail, you would probably need an adapter fitting to connect the gauge.

there is a test fitting also called a Schraeder valve on the fuel rail. Yes it has a black cap that resembles a tire valve stem cap. you then connect a fuel pressure tester by screwing it onto the fitting. Then start the vehicle and check the reading (psi) against what the manufacturer specification says. A good reading is about 35 psi. if it's 34 or lower you may have a problem at the fuel pressure regulator or the fuel pump itself. check your readings first before buying any new parts. Hope this helps you find your problem.

brian/ga