MD17C Cold Start Device

[Sir Rondo Normal]

Wondering if anyone here has had any experience with setting up the control rod travel on the md17c injection pump?

Specifically, in the manual it says to measure the distance from the timing gear cover to the control rod when it is fully pushed in and then again when it is fully in the back position. Making sure the difference is within specs. The confusing part is that is says the cold start device must be disengaged and to do so by using a special tool and pushing forward on the pin. This is where I'm befuddled. From the picture in the manual it doesn't look possible if I am understanding what this pin actually is.
It would be ultra-cool if there was someone on this forum who knows what I'm talking about and can clear things up for me.

Thanks,

Ron

[DougR]

Hello Ron,

The cold start "pin" is controlled by engine oil pressure. When the engine is not running the lack of oil pressure allows the pin to drop down and move toward the rear of the engine, thereby allowing the governor linkage and the control rod ( fuel pump rack) to move toward the rear further than it would move if the engine were actually running.

By using the tool to hold the cold start pin up and toward the front of the engine, you are duplicating running conditions and are thereby able to make an accurate measurement of the control rod travel.

You might also notice that the cold start pin must be held up during the timing procedure. This is because when the engine is not running, the pin drops, automatically allowing the injection pump to go to the cold start position, retarding the injection timing by several degrees. Holding the pin up in the running position allows accurate timing.

DougR

[Sir Rondo Normal]

Oh I see, perfect! So what you are actually doing is lifting it up, not pushing it forward. That makes perfect sense now. I was also confused about why that pin was just allowed to flop around in there and was looking for a socket for it to fit into to hold it up and couldn't see how it had anything to do with cold starts.

That manual certainly is not very clear.


It looks like I am going to have to add another gasket to the shims as well.

It's a difficult thing to work on, as you can't really see in there to see how things work.
Somehow something has changed with the shutdown mechanism too. I now have to fiddle with the cable before I can restart the engine. It's not the cable adjustment though, the problem seems to be inside. I can shutdown by working the lever by hand and it still doesn't reset properly.

Anyway, hopefully I can get this sorted out this week.

Thanks very much for your help.

Cheers