Originally Posted by rickmay

Diseasel300, I have read many posts where you need to stretch the spring to 27mm for good performance in the old valve. My spring was 20.5mm long. The new spring is thinner and shorter but the valve seems to operate on the same principle as the old valve. Both versions have a ball bearing first (the valve)in the path followed by the spring which logically should be calibrated to maintain a certain static pressure of fuel delivery to the IP. While a Bosch repair company says this new valve is the direct replacement for the valve I have, it stands to reason that if it opened at a lesser pressure, things won't be good.


I replaced the primer pump with a new Monarch pump. I closed this firmly after priming the system. How do you test the lift pump when the engine is not running? Do you know what causes these lift pumps to fail and at how many miles? I am at 156,000 miles.