I just put a fuel pressure gauge in my truck & it's an ISSPRO EV2 so it's electronic & I got the sensor on the regulator. When I started my truck the gauge is bouncing between 30-60 & pauses a little. Then driving it bounces kind of everywhere but mostly between 25-50 & also sometimes pauses at around 60 jus for a second. I was wondering if this is normal for the gauge to bounce or should it be giving a smooth reading?

 

its a mechanical fuel pump so it never maintains a constant pressure

 

I get a steady reading on my tree gauge. It will move between 50 and 70 but at idle it stays steady around 60. did you take your Schrader valve out of the fuel pressure regulator and tap in there?

 

Mine also reads steady between 50-70 psi... but read from a mechanical gauge tapped in at the Schrader valve. Idle, mine is just about 54 psi. I've heard others sat theirs ran fine, but there readings were sporadic and fluctuated... and others told them it was just the pump and the injectors working. If that were true, then I don't know why mine is smooth and seems normal. I do have a brand new pump in it...