Cm 2350 surging at high idle

[Rawze]

The fuel rail on them rises to pressure "X" then the pump bypasses. After the pressure drops off from use of the fuel down about 200-300 psi or so,.. the fuel pump kicks back in and re-pressurizes the system. It is known as a bypass-charging system. This cycling of the pump and pressure has 2 effects. It causes slightly higher engine load when it kicks in, and as it falls off, it effects injection slightly.

I would imagine that as the engine and systems get older,.. or if you went from 3 pistons to only 2, this fluctuation could get more pronounced. - I doubt there is a complete cure, as it is designed to work that way. Even so, it should be quite subtle, but i would imagine that contaminents, clogged lines, screens, and.or filters, or perhaps moisture or a bit of air in the fuel would make it worse.

Just my own thoughts, I don't own one.