OM 403 Diesel problem

What sort of stop control? Is it reaching high idle and staying there or just continuing to overspeed?

It sounds a bit like a fuel oil of some sort is getting in other than by the injector pump. I've heard this can happen when turbochargers oil seals fail.

AJH

The stop control is a separate lever. It is, in my opinion, continuing to overspeed, i.e. maximum no-load speed. The engine is non turbo-charged.

I think your reply is ambiguous, to my mind maximum no load speed is maximum governed rpm, if it's reaching this and then staying at this speed the governor is regulating the fuel. So something is stopping the governor from reacting to the speed control. Either a broken return spring or a bit of rust and crud jamming something?

AJH

Is it a marine engine with variable-speed governor, or a genset engine with fixed speed governor??

If it is fixed speed then you'll need to get it modified by a Bosch agent for variable-speed operation.

Other wise, the in-line pumps are pretty bullet-proof and have their own feed from the engine, so rust in the governor shoudn't be a problem.

I'm certainly no expert but doesn't the fact that the stop lever is ineffective suggest that something is either stuck or misassembled? ttfn Roland

It sounds to me like the fuel rack is stuck in the start position which is probably near full open for easy starting I would guess.

Hmm...thinking about it a bit more, does this engine have a butterfly valve in the air intake? We used to have an OM363 four cylinder Mercedes in a yacht and this used a venturi throttle system with butterfly valve..

An air line ran to a diaphragm on the fuel injection pump that operated the rack, at idle there was high vacuum that would pull the rack back to the idle position. Quite smart but when the butterfly valve would seize in the body from lack of use, high moisture etc., this would would allow the engine to run flat out. Worth a shot I guess

But hey, what do I know.

Chris Kessell

Worth looking at, but if it had an electrical solenoid shut-down, then you may have problems using the lever manually if it is held open by the solenoid.

Peter

Worth looking at, but if it had an electrical solenoid shut-down, then you may have problems using the lever manually if it is held open by the solenoid.

Peter