using a hand held fuel guage

[tdawg]

I have a cm870 and checking the fuel pressure at idle it jumps from 180 to 280 very fast, cant take a reading. If I rev the rpms to 1500 and hold it there, it will hold steady at 260. Is this normal?

[tree98]

Try a different gauge and see if it does the same thing, could be a faulty gauge. I think 260 is within spec, maybe at the lower end of the spectrum though.

[tdawg]

its not the gauge, the whole line is vibrating at idle.

[DDlighttruck]

How old are the fuel lines?

[tdawg]

2005 volvo and lines are original but not seeing bubles or fluctuation in the davco water separator.

[tdawg]

I changed the gear pump with another used one I had and seems to have a 10 to 15 psi more. It stays up at 275psi at 1500rpm. Going to run it this week see how it does.