[Leaky_7.3]

Recently my 97 F250 7.3 was at the shop and the mechanic noticed the fuel pressure fluctuating. I noticed this but never thought anything of it. When I am on the throttle it stays pretty much at a constant pressure but when I let off and coast it may fluctuate anywhere between 40-60 psi and sometime at idle may go to almost 25 at times and jump all around. The fuel pump was replaced a few months ago so what could be causing this fluctuation in pressure so what would cause this fluctuation?

 

[White95f250]

It's a mechanical pump so it will pulse at idle. If it is not running rough or have any performance issues then you are fine.

You can make sure your FPR screen is clean and a new Fuel Pressure Spring that is a "problem solver" spring. A little shorter but stiffer to prevent binding.