Perkins fuel metering valve - stuck, or something else?

[Marathon1150]

We have had a series of issues with our Perkins 4.108 related to but not restricted to, diesel in the oil. We have replaced the seals on the injection pump (problem persisted), replaced the mechanical lift pump with an electric pump (problem persisted), had the injectors serviced and blocked the passage from the cold start device (apparently another possible source of the diesel in oil problem). When the injectors were being re-installed, a couple more installation problems popped up (stripped bolt hole and a fractured injector clamp) but repaired. However, the engine was restarted quite easily, but the engine will no longer idle.

The engine starts nearly instantly, but climbs to about 2100-2200 RPM and stays there. The local injection/injector shop believes that it is a stuck fuel metering valve in the injection pump. And that this may result from not running the engine for long periods of time. But the engine was running fairly regularly over the several months leading up to re and re the injectors.

Two questions. Can anything else prevent a Perkins 4.108 from idling normally, and responding normally to the throttle controls? And, can a stuck fuel metering valve be unstuck without removing the injection pump?

[Lepke]

Unless the throttle cable is pulling on the injector pump lever, the problem is in the injector pump. Diesels are simple. Give it more fuel and it goes faster. When you work on an injector pump you need to be hospital clean. A small piece of dirt can jam things. If you can't be that clean, it's better to have yours done or buy a rebuild.